Broadband spectral response multiplication type organic photoelectric detector

Abstract

The invention discloses a broadband spectral response multiplication type organic photoelectric detector which comprises a substrate, a transparent conducting layer, an anode modifying layer, a photosensitive layer, a hole blocking layer and a cathode layer which are sequentially stacked and arranged, wherein the photosensitive layer is prepared from a mixture containing an organic micromoleculardonor material (BODIPY) and an organic micromolecular acceptor material (PC61BM or PC71BM); the BODIPY is an organic fluorescent dye with a very high molar absorption coefficient and a wide absorptionrange and has obvious photoelectric response at an infrared waveband, so that a broadband spectral response function of a photoelectric detector is achieved, a response degree or an external quantumefficiency for detecting optical signals is remarkably improved, EQE can exceed 100% under the forward bias, and the maximum EQE can reach 350% or more. The device has the advantages of simple structure and manufacturing technology, low cost, application to large-area preparation and great advantage in the field of organic photoelectric detectors.

Description

technical field [0001] The invention belongs to the technical field of photoelectric materials, and in particular relates to a multiplication type organic photodetector with wide spectral response. Background technique [0002] A photodetector is a device that converts an optical signal into an electrical signal (current or voltage). After processing by a subsequent circuit system, the system can respond to the optical signal, and can also restore the electrical signal to an optical signal. According to the different response wavelength ranges of photodetectors, they can be divided into wide spectral response photodetectors and narrow spectral response photodetectors. Among them, photodetectors with wide spectral response have important applications in many aspects such as image sensing, remote control, and day and night surveillance. [0003] According to the different types of photodetectors, two-terminal photodetectors can be divided into photodiodes and avalanche photod...

AI Technical Summary

Problems solved by technology

[0003] According to the different types of photodetectors, two-terminal photodetectors can be divided into photodiodes and avalanche photodiodes. They are all photovoltaic devices, in which photodiodes have no internal gain, and the upper limit of their external quantum efficiency (EQE) is 100%, that is, there is no multiplication effect on the incident light signal; the avalanche photodiode can have a multiplication effect on the photogenerated carriers, so its external quantum efficiency can exceed 100%, but the avalanche photodiode is generally made of inorganic semiconductor materials. The production process is complicated, the cost is high, and the applied bias voltage is high (100-200V), the dark current is large, it needs to work in a low temperature environment, and there are many restrictive conditions

[0004] Compared with inorganic photodetectors, organic photodetectors have the advantages of good flexibility, low manufacturing cost, large-scale preparation and wide range of material selection, but the response range of organic photodetectors is usually limited to the near-ultraviolet to visible light band. , there are not many reports on organic photodetectors with high responsivity in the near-infrared light. There is a certain energy level difference between the donor-acceptor material, and the detection of near-infrared light requires a small energy gap, and the decrease of the energy gap makes it difficult to obtain a material with a high degree of energy level matching with the acceptor material; the energy gap Reduction facilitates exciton recombination and reduces carrier generation efficiency

In addition, there are few reports on organic photodetectors that have a multiplier effect on near-infrared light, and almost all photodetectors work under reverse bias (the anode is connected to negative voltage) and can work under forward bias. Moreover, there are no relevant reports on photodetectors with a multiplication effect.

Images