Up-conversion device based on integration of InGaAs detector and laminated OLED and preparation method of up-conversion device

Abstract

The invention relates to an up-converter based on integration of an InGaAs detector and a laminated OLED and a preparation method, and belongs to the technical field of semiconductors. The detector unit adopted by the invention is an InGaAs infrared detector with an n-i-p structure, and has excellent photoelectric response characteristic to short-wave infrared, and the peak wavelength is 1.55 [mu] m. The light-emitting unit adopts an OLED device with a laminated structure, and the light-emitting efficiency of a single-junction OLED device can be twice that of the single-junction OLED device, so that the light-light conversion efficiency of the up-conversion device is effectively improved. The metal reflecting layer is introduced between the detector and the light-emitting device, so that the light response characteristic of the detector and the light emitting efficiency of the light-emitting device can be effectively improved, and the light-light conversion efficiency of the up-conversion device is further improved. And by combining a composite sealing technology, the service life of the up-conversion device can be effectively prolonged. The efficient and stable short-wave infrared up-conversion device has huge application potential in the field of military night vision application.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to an up-converter based on the integration of an InGaAs detector and a stacked OLED and a preparation method thereof. Background Art

[0002] Short-wave infrared (0.9-2.5μm) can be radiation emitted by the object itself or light reflected by the object itself, and is not affected by atmospheric distortion, haze, dust, smoke, etc. Therefore, the short-wave infrared optical system can passively obtain target information and has good concealment and security; short-wave infrared images will have shadows and contrasts, and have resolution and detail features comparable to visible light images, which can enhance recognition capabilities. At the same time, ambient starlight and night background light can both serve as natural illuminants for short-wave infrared, providing illumination for night imaging, and can be better used for night vision imaging.

[0003] Infrared photoelectric detection and imaging devices play an important role in biological detection, information communication, military, meteorology and other fields. Traditional imaging devices require the integration of infrared photodetectors and readout circuits, and the complex integration process limits the development of infrared imaging systems. As an alternative solution, upconversion devices have the advantages of simple process and no need to be integrated with readout circuits, and can directly convert infrared light into visible light for imaging. At present, most of the reported upconversion devices are all-organic devices that integrate organic photodetectors and organic light-emitting diodes (OLEDs). Although they have achieved high photon-photon conversion efficiency, they are limited by the light response range of organic photosensitive materials. Most all-organic upconversion devices can convert wavelengths less than 1000 nm, which greatly limits the application range of upconversion devices.

[0004] The "Research Progress of Infrared Up-conversion Devices Based on OLED Display Units" published by Chen Jun and the "Research Progress of Optical Up-converters of Infrared Detectors Integrated with OLEDs" published by Li Huisong disclosed up-converters integrating InGaAs detectors with OLEDs. However, due to the immature research on the inorganic-organic interface mechanism, the infrared-to-visible light conversion efficiency of the up-conversion devices is low. Summary of the invention

[0005] In view of the shortcomings and deficiencies of the above prior art, the main purpose of the present invention is to provide an up-converter based on the integration of InGaAs detector and stacked OLED and a preparation method thereof.

[0006] The purpose of the present invention is achieved through the following technical solutions: An upconverter based on the integration of an InGaAs detector and a stacked OLED, characterized in that the OLED device sequentially comprises a substrate, a bottom electrode, an n-type InP layer, an InGaAs detection layer, a p-type InP layer, a metal reflective layer, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, an electron generating layer, a hole generating layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, a metal cathode, a covering layer and a sealing layer.

[0007] The substrate is InP or single crystal silicon.

[0008] Furthermore, the bottom electrode is Ti / Al / Ti, Ti / Al / Mo or Ti / Al / ITO; the thickness of each layer of the bottom electrode 3 is 15 nm / 40 nm / 5 nm.

[0009] Furthermore, the n-type layer is n-InP, the i-type layer is InGaAs, and the p-type layer is p-InP.

[0010] Furthermore, the metal reflective layer is Ti / Al / Ti or Ti / Al / Mo; the thickness of each layer of the metal reflective layer is 15 nm / 40 nm / 5 nm.

[0011] Furthermore, the hole injection layer is HAT-CN, F4-TCNQ or NDP-9; and the thickness of the hole injection layer is 5-20 nm.

[0012] Furthermore, the hole transport layer is TAPC, NPB, TCTA or m-MTDATA; the thickness of the hole transport layer is 10-50 nm.

[0013] Furthermore, the electron blocking layer is TCTA or mCP; the thickness of the electron blocking layer is 1-10 nm.

[0014] Furthermore, the light-emitting layer is a mixed material of a host material and a guest material, wherein the host material is CBP or TCTA, the guest material is Ir(ppy)2 or Ir(ppy)3, and the doping concentration of the guest material is 5% to 15%; the thickness of the light-emitting layer is 20 to 40 nm.

[0015] Furthermore, the hole blocking layer is Bepp2 or DPEPO; the thickness of the hole blocking layer is 1-10 nm.

[0016] Furthermore, the electron transport layer is BmPyPb, TPBi or Bphen; and the thickness of the electron transport layer is 10-30 nm.

[0017] Furthermore, the electron injection layer is Liq or LiF; the thickness of the electron injection layer is 1-2 nm.

[0018] Furthermore, the electron generation layer is Bphen:Yb or Bphen:Cs2CO3, and the doping concentration is 1%~10%; the thickness of the electron generation layer is 5~10 nm.

[0019] Furthermore, the hole generating layer is NPB:F4-TCNQ or TAPC:HAT-CN, and the doping concentration is 1% to 10%; the thickness of the hole generating layer is 5 to 10 nm.

[0020] Furthermore, the metal cathode is Al, Ag or Mg:Ag, and the thickness of the metal cathode is 10-20 nm.

[0021] Furthermore, the covering layer is Alq3 or ZnSe, and the thickness of the covering layer is 30-60 nm.

[0022] Furthermore, the sealing layer is Al2O3 / Parylene / SiO2 or Al2O3 / SiN x / SiO2 composite structure, the sealing layer thickness is 180 nm / 500~1000 nm / 70 nm.

[0023] The preparation method of an up-converter based on the integration of an InGaAs detector and a stacked OLED comprises the following steps: 1) Etching the InGaAs detector epitaxial substrate by ultraviolet lithography and inductively coupled plasma etching to obtain an independent infrared detector platform structure and reserve a bottom electrode position; 2) A SiO2 passivation layer is prepared on the surface by a plasma enhanced chemical vapor deposition method, and the SiO2 passivation layer is subjected to secondary photolithography and ICP etching; 3) Prepare the bottom electrode, cathode ring and metal reflective layer by magnetron sputtering; 4) vacuum evaporating a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, an electron generating layer, a hole generating layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, a metal cathode, and a covering layer in sequence; 5) A sealing layer of the composite structure is prepared by atomic layer deposition, molecular layer deposition or PECVD to finally obtain an upconverter.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1) The up-conversion device of the present invention integrating the InGaAs infrared detector and the stacked OLED introduces a metal reflective layer to improve the utilization rate of the InGaAs detector for infrared light and the light extraction efficiency of the visible light of the OLED, thereby improving the detector light response characteristics and the luminous efficiency of the OLED, thereby obtaining a high-performance up-conversion device.

[0025] 2) The up-conversion device of the present invention integrating the InGaAs infrared detector and the stacked OLED can effectively improve the luminous efficiency of the OLED by designing the stacked OLED device structure, thereby improving the light-to-light conversion efficiency of the up-conversion device.

[0026] 3) The up-conversion device of the present invention, which integrates the InGaAs infrared detector and the stacked OLED, uses InGaAs as the detector part, and can have excellent light response characteristics to short-wave infrared. At the same time, combined with the composite sealing technology, it can ensure that the prepared up-conversion device has good stability, and has great application potential in the field of military night vision applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is a schematic diagram of the structure and working process of the up-converter based on the integration of InGaAs detector and OLED prepared in Example 1 of the present invention.

[0029] Figure 2 This is a schematic diagram of the structure and working process of the up-converter based on the integration of InGaAs detector and OLED prepared in Comparative Example 1 of the present invention.

[0030] Figure 3 This is the preparation process of the upconverter of Example 1 and Comparative Example 1 in the present invention.

[0031] Figure 4 It is a top view of the upconverter preparation process of Example 1 and Comparative Example 1 in the present invention.

[0032] Figure 5 The current efficiency-brightness curves of the single-junction and stacked-layer structure green OLED devices in Example 1 and Comparative Example 1 of the present invention.

[0033] Wherein: substrate 1, bottom electrode 2, n-type InP layer 3, InGaAs detection layer 4, p-type InP layer 5, metal reflective layer 6, hole injection layer 7, hole transport layer 8, electron blocking layer 9, light-emitting layer 10, hole blocking layer 11, electron transport layer 12, electron injection layer 13, electron generation layer 14, hole generation layer 15, hole transport layer 16, electron blocking layer 17, light-emitting layer 18, hole blocking layer 19, electron transport layer 20, electron injection layer 21, metal cathode 22, covering layer 23, sealing layer 24. DETAILED DESCRIPTION

[0034] In order to further understand the present invention, preferred embodiments of the present invention are described below. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0035] Example 1: Figure 1 As shown, the up-conversion device based on the integration of InGaAs infrared detector and stacked OLED includes a substrate 1, a bottom electrode 2, an n-type layer 3, a substrate 1, a bottom electrode 2, an n-type InP layer 3, an InGaAs detection layer 4, a p-type InP layer 5, a metal reflective layer 6, a hole injection layer 7, a hole transport layer 8, an electron blocking layer 9, a light-emitting layer 10, a hole blocking layer 11, an electron transport layer 12, an electron injection layer 13, a metal cathode 22, a covering layer 23 and a sealing layer 24 which are arranged in sequence.

[0036] In this embodiment, the substrate is InP; the bottom electrode is Ti / Al / Ti, and its thickness is 15 nm / 40 nm / 5 nm; the metal reflective layer is Ti / Al / Ti, and its thickness is 15 nm / 40 nm / 5 nm; the hole injection layer is HAT-CN, and its thickness is 10 nm; the hole transport layer is TAPC, and its thickness is 30 nm; the electron blocking layer is TCTA, and its thickness is 5 nm; the light-emitting layer is a blended film of the host material and the guest material, and its thickness is 30 nm. Among them, the main material is CBP, the guest material is Ir(ppy)3, and the doping concentration of the guest material is 8%; the hole blocking layer is Bepp2, and its thickness is 3 nm; the electron transport material is Bphen, and its thickness is 20 nm; the electron injection material is Liq, and its thickness is 1 nm; the cathode is Mg:Ag, and its doping concentration is 10%, and its thickness is 14 nm; the covering layer is Alq3, and its thickness is 30~60 nm; the sealing layer is an Al2O3 / Parylene / SiO2 composite structure, and its thickness is 180 nm / 900 nm / 70 nm.

[0037] The specific preparation method of the up-conversion device based on the integration of InGaAs infrared detector and OLED in this embodiment is as follows: The InGaAs detector epitaxial substrate was obtained by ultraviolet lithography and reactive ion etching (RIE). Spin-coat the photoresist AZ6130 on the surface of the InGaAs detector epitaxial substrate at a spin-coating speed of 2000~3000r / min; irradiate the photoresist with ultraviolet light through a patterned mask, and the corresponding mesa area size is 10.82mm × 14.82 mm; place the epitaxial wafer on a hot plate for hard film baking treatment, and heat it at 70~90℃ for 10~15min; after cooling to room temperature, put the epitaxial wafer into a plasma cleaning machine, and introduce O2 at a flow rate of 150~250sccm, and clean it for 80~100s at a power of 200~300W to remove the residual photoresist; evacuate the vacuum chamber of the RIE etcher to below 1Pa, maintain the chamber temperature at 10~25℃, and introduce SiCl4, Cl2 and Ar process gases with a purity of more than 99.99%, with gas flow rates of 50~100sccm, 5~10sccm and 5~10sccm respectively. The chamber pressure was controlled at 0.5~1.0 Pa. After the pressure was stable for 20~30 s, etching was performed with a radio frequency power of 100~150 W. EDS was used to monitor the etching rate during the process to ensure that the etching angle was 80~90°. The InP substrate surface was photolithographically etched to carve out the InGaAs infrared detector platform and the bottom electrode position. The surface photoresist was removed using acetone solution.

[0038] The SiO2 thin film passivation layer was prepared by PECVD. The deposition chamber was evacuated to below 1 Pa, the chamber temperature was maintained at 100-220°C, and SiH4, O2 and Ar process gases with a purity of more than 99.99% were introduced, with gas flow rates of 10-15 sccm, 5-10 sccm and 120-150 sccm respectively; the chamber pressure was controlled at 0.5-1.0 Pa, and after the pressure was stable for 20-30 s, a layer of SiO2 thin film was prepared on the surface of the above-mentioned substrate after photolithography using a radio frequency power of 250-300 W to form isolation between devices.

[0039] The bottom electrode, cathode ring and metal reflective layer were etched on the SiO2 film by UV lithography and ICP etching. The photoresist AZ6130 was spin-coated on the surface of the InGaAs detector epitaxial substrate at a spin-coating speed of 2000-3000 r / min. The UV light was irradiated on the photoresist through the patterned mask. The corresponding bottom electrode, cathode ring and metal reflective layer area sizes were 1mm × 3 mm, 10.42 mm × 14.42 mm (width 0.18 mm) and 4.5 mm × 4.5 mm, respectively. The epitaxial wafer was placed on a hot plate for hard film baking treatment, and heated at 70-90℃ for 10-15 min. After cooling to room temperature, the epitaxial wafer was placed in a plasma cleaning machine, and the O2 flow rate was 150-250 sccm. The cleaning was carried out at a power of 200-300 W for 80-100 s to remove the residual photoresist. The vacuum chamber of the ICP etcher was evacuated to 1 Pa, the temperature is maintained at 10~25℃, and O2 and SF6 process gases with a purity of more than 99.99% are introduced, with gas flow rates of 20~60 sccm and 5~15 sccm respectively. The RF power of the upper electrode and the lower electrode are set to 220~300 W and 120~160 W respectively. The chamber pressure is maintained at 0.5~1.0 Pa, and etching is started after the pressure is stable for 20~30s, the time is 12~15 min, and the surface of the p-type layer is photolithographically etched to the position of the top electrode, cathode ring and metal reflective layer; the surface photoresist is removed using acetone solution.

[0040] The top electrode, cathode ring and metal reflective layer were prepared by ultraviolet lithography and magnetron sputtering. The photoresist AZ6130 was spin-coated on the surface of the InGaAs detector epitaxial substrate at a spin-coating speed of 2000~3000r / min; ultraviolet light was irradiated on the photoresist through a patterned mask, and the corresponding bottom electrode, cathode ring and metal reflective layer area sizes were 1 mm × 3 mm, 10.42 mm × 14.42 mm (width 0.18 mm) and 4.5 mm × 4.5 mm, respectively; the epitaxial wafer was placed on a hot plate for hard film baking treatment, and heated at 70~90℃ for 10~15min; after cooling to room temperature, the epitaxial wafer was placed in a plasma cleaning machine, and the flow rate of O2 was 150~250sccm, and the cleaning was carried out at a power of 200~300W for 80~100s to remove the residual photoresist; the vacuum chamber was evacuated to 10 -4 Pa, Ar process gas with a purity of more than 99.99% was introduced, the flow rate of Ar was 100 sccm, the chamber pressure was maintained at 1~2 Pa, Ti and Al were sputtered at powers of 180~200 W and 100~150 W, respectively, to prepare a bottom electrode, cathode ring and metal reflective layer with a structure of Ti / Al / Ti (15 nm / 40 nm / 5 nm); the photoresist on the surface was removed using acetone solution.

[0041] Finally, vacuum evaporation is performed in sequence to form a hole injection layer 7, a hole transport layer 8, an electron blocking layer 9, a light-emitting layer 10, a hole blocking layer 11, an electron transport layer 12, an electron injection layer 13, a metal cathode 22, and a capping layer 23. In order to improve the service life of the up-conversion device, a sealing layer 24 is prepared on the top of the up-conversion device. Al2O3 thin film is prepared by ALD, Parylene thin film is prepared by MLD method, and SiO2 thin film is prepared by PECVD method to obtain a complete sealing layer structure. Finally, an up-conversion device integrating InGaAs infrared detector and OLED is obtained. The structure of the up-conversion device is InP / Ti(15 nm) / Al(40 nm) / Ti(5 nm) / n-InP / InGaAs / p-InP / Ti(15nm) / Al(40 nm) / Ti(5 nm) / HAT-CN(10 nm) / TAPC(30 nm) / TCTA(5 nm) / CBP:8% Ir(ppy)3(30 nm) / Bepp2(3 nm) / Bphen(20 nm) / Liq(1nm) / Mg:10%Ag(14nm) / Alq3(55nm) / Al2O3(180nm) / Parylene(900 nm) / SiO2(70 nm).

[0042] Attached Figure 1 The schematic diagram of the structure and working process of the up-conversion device prepared in Example 1 of the present invention. The InGaAs detector with nip structure is used as the detection unit, which has excellent photoelectric response characteristics for short-wave infrared, and the peak wavelength is located at 1.55 μm. When short-wave infrared light is incident on the up-conversion device from the bottom of the substrate, the InGaAs layer absorbs photons and generates excitons, and the excitons are separated into photogenerated electrons and photogenerated holes under the action of the electric field. The photogenerated electrons are transmitted to the anode and collected, and the photogenerated holes are transmitted to the cathode. The introduction of the metal reflective layer can reflect the short-wave infrared light that is not absorbed by InGaAs, and further absorbed by InGaAs, thereby increasing the light response characteristics of the InGaAs infrared detector. On the other hand, the photogenerated holes and the electrons injected by the cathode recombine in the light-emitting layer of the green light OLED device, causing the OLED device to be lit, thereby realizing the conversion of short-wave infrared light into green visible light. The light emitted by the OLED device is directed in all directions, and the light in the direction of the substrate can be reflected by the metal reflective layer, thereby further increasing the light extraction efficiency of the OLED device. Therefore, the up-conversion device based on the integration of InGaAs detector and OLED in this embodiment can achieve high up-conversion efficiency.

[0043] Attached Figure 3This is the preparation process of the up-conversion device in Example 1 and Comparative Example 1 of the present invention. The specific steps include etching the InGaAs detector epitaxial substrate by UV lithography and RIE method; preparing the SiO2 thin film passivation layer by PECVD method; engraving the positions of each metal layer in the SiO2 thin film by UV lithography and ICP method; preparing the bottom electrode, cathode ring and metal reflective layer by magnetron sputtering method; vacuum evaporation of OLED device; and preparing the composite structure sealing layer.

[0044] Attached Figure 4 The top view of the preparation process of the up-conversion device in Example 1 and Comparative Example 1 of the present invention. The specific steps include: (1) nip structure InGaAs detector epitaxial substrate; (2) photolithography of InGaAs detector platform and bottom electrode position; (3) PEDVD preparation of SiO2 film; (4) photolithography of bottom electrode, metal reflective layer, cathode ring position, and preparation of each metal layer; (5) vacuum evaporation of each organic layer of OLED device in sequence; (6) vacuum evaporation of cathode, and connection of cathode with cathode ring for testing.

[0045] Comparative Example 1: Figure 2 As shown, the up-conversion device based on the integration of InGaAs detector and OLED includes a substrate 1, a bottom electrode 2, an n-type layer 3, an i-type layer 4, a p-type layer 5, a metal reflective layer 6, a hole injection layer 7, a hole transport layer 8, an electron blocking layer 9, a light-emitting layer 10, a hole blocking layer 11, an electron transport layer 12, an electron injection layer 13, an electron generating layer 14, a hole generating layer 15, a hole transport layer 16, an electron blocking layer 17, a light-emitting layer 18, a hole blocking layer 19, an electron transport layer 20, an electron injection layer 21, a metal cathode 22, a covering layer 23 and a sealing layer 24, which are arranged in sequence.

[0046] In this embodiment, the substrate is InP; the bottom electrode is Ti / Al / Ti with a thickness of 15 nm / 40 nm / 5 nm; the n-type layer is n-InP, the i-type layer is InGaAs, and the p-type layer is p-InP; the metal reflective layer is Ti / Al / Ti with a thickness of 15 nm / 40 nm / 5 nm; the hole injection layer is HAT-CN with a thickness of 10 nm; the hole transport layer is TAPC with a thickness of 30 nm; the electron blocking layer is TCTA with a thickness of 5 nm; the light-emitting layer is a blended film of the host material and the guest material with a thickness of 30 nm. Among them, the main material is CBP, the guest material is Ir(ppy)3, and the doping concentration of the guest material is 8%; the hole blocking layer is Bepp2, and its thickness is 3 nm; the electron transport material is Bphen, and its thickness is 20 nm; the electron injection material is Liq, and its thickness is 1 nm; the electron generation layer is Bphen:Yb, and its doping concentration is 5%, and its thickness is 6 nm; the hole generation layer is TAPC:HAT-CN, and its doping concentration is 5%, and its thickness is 5 nm; the cathode is Mg:Ag, and its doping concentration is 10%, and its thickness is 14 nm; the covering layer is Alq3, and its thickness is 30~60 nm; the sealing layer is an Al2O3 / Parylene / SiO2 composite structure, and its thickness is 180 nm / 900 nm / 70 nm.

[0047] The specific preparation method of the up-converter based on the integration of InGaAs detector and OLED in this embodiment is as follows: The InGaAs epitaxial platform was obtained by UV lithography and RIE. Spin-coat the photoresist AZ6130 on the surface of the InGaAs detector epitaxial substrate at a spin-coating speed of 2000-3000 r / min; irradiate the photoresist with ultraviolet light through a patterned mask, and the corresponding mesa area size is 10.82 mm × 14.82 mm; place the epitaxial wafer on a hot plate for hard film baking treatment, and heat it at 70-90°C for 10-15 minutes; after cooling to room temperature, put the epitaxial wafer into a plasma cleaning machine, and introduce O2 at a flow rate of 150-250 sccm, and clean it for 80-100 seconds at a power of 200-300 W to remove the residual photoresist; evacuate the vacuum chamber of the RIE etcher to below 1 Pa, maintain the chamber temperature at 10-25°C, and introduce SiCl4, Cl2 and Ar process gases with a purity of more than 99.99%, with gas flow rates of 50-100 sccm, 5-10 sccm and 5-10 sccm, respectively. The chamber pressure was controlled at 0.5~1.0Pa. After the pressure was stable for 20~30 s, etching was performed with a radio frequency power of 100~150 W. EDS was used to monitor the etching rate during the process to ensure that the etching angle was 80~90°. The InP substrate surface was photolithographically etched to carve out the InGaAs infrared detector platform and the bottom electrode position. The surface photoresist was removed using acetone solution.

[0048] The SiO2 thin film passivation layer was prepared by PECVD. The deposition chamber was evacuated to below 1 Pa, the chamber temperature was maintained at 100-220°C, and SiH4, O2 and Ar process gases with a purity of more than 99.99% were introduced, with gas flow rates of 10-15 sccm, 5-10 sccm and 120-150 sccm respectively; the chamber pressure was controlled at 0.5-1.0 Pa, and after the pressure was stable for 20-30 s, a layer of SiO2 thin film was prepared on the surface of the above-mentioned substrate after photolithography using a radio frequency power of 250-300 W to form isolation between devices.

[0049] The bottom electrode, cathode ring and metal reflective layer were etched on the SiO2 film by UV lithography and ICP etching. The photoresist AZ6130 was spin-coated on the surface of the InGaAs detector epitaxial substrate at a spin-coating speed of 2000-3000 r / min. The UV light was irradiated on the photoresist through the patterned mask. The corresponding bottom electrode, cathode ring and metal reflective layer area sizes were 1mm × 3 mm, 10.42 mm × 14.42 mm (width 0.18 mm) and 4.5 mm × 4.5 mm, respectively. The epitaxial wafer was placed on a hot plate for hard film baking treatment, and heated at 70-90℃ for 10-15 min. After cooling to room temperature, the epitaxial wafer was placed in a plasma cleaning machine, and the O2 flow rate was 150-250 sccm. The cleaning was carried out at a power of 200-300 W for 80-100 s to remove the residual photoresist. The vacuum chamber of the ICP etcher was evacuated to 1 Pa, the temperature is maintained at 10~25℃, and O2 and SF6 process gases with a purity of more than 99.99% are introduced, with gas flow rates of 20~60 sccm and 5~15 sccm respectively. The RF power of the upper electrode and the lower electrode are set to 220~300 W and 120~160 W respectively. The chamber pressure is maintained at 0.5~1.0 Pa, and etching is started after the pressure is stable for 20~30s, the time is 12~15 min, and the surface of the p-type layer is photolithographically etched to the position of the top electrode, cathode ring and metal reflective layer; the surface photoresist is removed using acetone solution.

[0050] The top electrode, cathode ring and metal reflective layer were prepared by ultraviolet lithography and magnetron sputtering. The photoresist AZ6130 was spin-coated on the surface of the InGaAs detector epitaxial substrate at a spin-coating speed of 2000~3000r / min; ultraviolet light was irradiated on the photoresist through a patterned mask, and the corresponding bottom electrode, cathode ring and metal reflective layer area sizes were 1 mm × 3 mm, 10.42 mm × 14.42 mm (width 0.18 mm) and 4.5 mm × 4.5 mm, respectively; the epitaxial wafer was placed on a hot plate for hard film baking treatment, and heated at 70~90℃ for 10~15min; after cooling to room temperature, the epitaxial wafer was placed in a plasma cleaning machine, and the flow rate of O2 was 150~250sccm, and the cleaning was carried out at a power of 200~300W for 80~100s to remove the residual photoresist; the vacuum chamber was evacuated to 10 -4 Pa, Ar process gas with a purity of more than 99.99% was introduced, the flow rate of Ar was 100 sccm, the chamber pressure was maintained at 1~2 Pa, Ti and Al were sputtered at powers of 180~200 W and 100~150 W, respectively, to prepare a bottom electrode, cathode ring and metal reflective layer with a structure of Ti / Al / Ti (15 nm / 40 nm / 5 nm); the photoresist on the surface was removed using acetone solution.

[0051] Finally, vacuum evaporation is performed in sequence to form a hole injection layer 7, a hole transport layer 8, an electron blocking layer 9, a light-emitting layer 10, a hole blocking layer 11, an electron transport layer 12, an electron injection layer 13, an electron generation layer 14, a hole generation layer 15, a hole transport layer 16, an electron blocking layer 17, a light-emitting layer 18, a hole blocking layer 19, an electron transport layer 20, an electron injection layer 21, a metal cathode 22 and a capping layer 23. In order to improve the service life of the up-conversion device, a sealing layer 24 is prepared on the top of the up-conversion device. Al2O3 thin film is prepared by ALD, Parylene thin film is prepared by MLD method, and SiO2 thin film is prepared by PECVD method to obtain a complete sealing layer structure. Finally, an up-conversion device integrating InGaAs infrared detector and stacked OLED is obtained. The structure of the up-conversion device is InP / Ti(15nm) / Al(40nm) / Ti(5nm) / n-InP / InGaAs / p-InP / Ti(15nm) / Al(40nm) / Ti(5nm) / HAT-CN(10nm) / TAPC(30nm) / TCTA(5nm) / CBP:8%Ir(ppy)3(30nm) / Bepp2(3nm) / Bphen(20nm) / Liq(1nm) / Bphen:5%Yb(6nm) / TAPC:5% HAT-CN(5nm) / TAPC(30nm) / TCTA(5nm) / CBP:8%Ir(ppy)3(30nm) / Bepp2(3nm) / Bphen(20nm) / Liq(1nm) / Mg:10%Ag(14nm) / Alq3(55nm) / Al2O3(180nm) nm) / Parylene(900nm) / SiO2(70nm).

[0052] Attached Figure 2The schematic diagram of the structure and working process of the up-conversion device prepared in comparative example 1 of the present invention. The InGaAs infrared detector with a nip structure is used as a detection unit, which has excellent photoelectric response characteristics for short-wave infrared, and the peak wavelength is located at 1.55 μm. When short-wave infrared light enters the up-conversion device from the bottom of the substrate, the InGaAs layer absorbs photons and generates excitons, and the excitons are separated into photogenerated electrons and photogenerated holes under the action of the electric field. Photogenerated electrons are transmitted to the anode and collected, and photogenerated holes are transmitted to the cathode. The introduction of the metal reflective layer can reflect the short-wave infrared light that is not absorbed by InGaAs, and further absorbed by InGaAs, thereby increasing the light response characteristics of the InGaAs infrared detector. On the other hand, the photogenerated holes and the electrons generated by the electron generation layer are recombined in the first light-emitting unit of the green light stacked OLED device, and the holes generated by the hole generation layer are recombined with the electrons injected by the cathode in the second light-emitting unit of the green light stacked OLED device, causing the OLED device to be lit, thereby realizing the conversion of short-wave infrared light into green visible light. Due to the use of a stacked structure, the luminous efficiency of OLED devices can be significantly improved, reaching ~2 times that of a single device. Figure 5 In addition, the light emitted by the OLED device is directed in all directions, and the light in the direction of the substrate can be reflected by the metal reflective layer, thereby further increasing the light extraction efficiency of the OLED device. Therefore, the up-conversion device based on the integration of the InGaAs infrared detector and the stacked OLED in this embodiment can achieve a higher up-conversion efficiency.

[0053] Attached Figure 3 This is the preparation process of the up-conversion device in Example 1 and Comparative Example 1 of the present invention. The specific steps include etching the InGaAs detector epitaxial substrate by UV lithography and RIE method; preparing the SiO2 thin film passivation layer by PECVD method; engraving the positions of each metal layer in the SiO2 thin film by UV lithography and ICP method; preparing the bottom electrode, cathode ring and metal reflective layer by magnetron sputtering method; vacuum evaporation of OLED device; and preparing the composite structure sealing layer.

Claims

1. An upconverter based on the integration of InGaAs detector and stacked OLED, characterized by The OLED device comprises, in sequence, a substrate, a bottom electrode, an n-type InP layer, an InGaAs detection layer, a p-type InP layer, a metal reflective layer, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, an electron generation layer, a hole generation layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, a metal cathode, a covering layer and a sealing layer, wherein: the metal reflective layer is Ti / Al / Ti or Ti / Al / Mo; and the thickness of each metal reflective layer is 15 nm / 40 nm / 5 nm.

2. The up-converter based on the integration of InGaAs detector and stacked OLED as claimed in claim 1, characterized in that The light-emitting layer is a mixture of a host material and a guest material, wherein the host material is CBP or TCTA, the guest material is Ir(ppy)2 or Ir(ppy)3, and the doping concentration of the guest material is 5%~15%; the thickness of the light-emitting layer is 20~40 nm.

3. A method for preparing an upconverter based on the integration of an InGaAs detector and an OLED, comprising the following steps: 1) Etching the InGaAs detector epitaxial substrate by ultraviolet lithography and inductively coupled plasma etching to obtain an independent infrared detector platform structure and reserve a bottom electrode position; 2) A SiO2 passivation layer is prepared on the surface by a plasma enhanced chemical vapor deposition method, and the SiO2 passivation layer is subjected to secondary photolithography and ICP etching; 3) Prepare the bottom electrode, cathode ring and metal reflective layer by magnetron sputtering; 4) vacuum evaporating a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, an electron generating layer, a hole generating layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, a metal cathode, and a covering layer in sequence; 5) A sealing layer of the composite structure is prepared by atomic layer deposition, molecular layer deposition or PECVD to finally obtain an upconverter.

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