11 results about "Free carrier absorption" patented technology

The application provides a TOPCon cell, which comprises a doped polysilicon layer; the doped polysilicon layer comprises a first doped polysilicon region and a second doped polysilicon alloy region; the first doped polysilicon region is selected from phosphorus-doped polysilicon; the second doped polysilicon alloy region is selected from phosphorus-doped polysilicon alloyed with at least one element selected from oxygen, carbon and nitrogen; the doping concentration of the first doped polysilicon region is not less than 1E20 cm ‑3 -3; the band gap of the second doped polysilicon alloy region is greater than that of the first doped polysilicon region, and the doping concentration of the second doped polysilicon alloy region is less than that of the first doped polysilicon region. The TOPCon cell structure provided by the application can ensure the thickness of the doped polysilicon in the metal contact region, avoid the destruction of the tunneling oxide layer in the slurry sintering process, reduce the recombination current and the contact resistance, and reduce the light parasitic absorption in the non-metal region, especially the free carrier absorption.

The application provides a TOPCon cell, comprising: a single crystal silicon wafer; an inner expansion layer arranged on the back surface of the single crystal silicon wafer; a doped polysilicon layer arranged below the inner expansion layer; the doped polysilicon layer comprises: a first doped polysilicon region and a second doped polysilicon region, the doping concentration of the first doped polysilicon region is higher than that of the second doped polysilicon region; the inner layer comprises: a first inner expansion region and a second inner expansion region, the position of the first inner expansion region corresponds to the position of the first doped polysilicon region, and the junction depth of the first inner expansion region is greater than that of the second inner expansion region. The TOPCon cell provided by the application has a specific structure, which can ensure the thickness and concentration of the doped polysilicon in the metal contact area, avoid the destruction of the tunneling oxide layer in the slurry sintering process, reduce the recombination current and the contact resistance, and at the same time, reduce the light parasitic absorption of the non-metal area, especially the free carrier absorption.

The invention relates to a method for measuring electrical properties of a semiconductor quantum dot material based on free carrier absorption. Comprising the following steps that pumping laser and continuous detection laser are sequentially emitted to the same position of a semiconductor sample to be detected, the power of the pumping laser is changed, the concentration of free carriers is subjected to nonlinear change, the nonlinear characteristic of the free carriers is closely related to the characteristics of excitons and carriers in quantum dots, and the concentration of the free carriers is detected. Transmitting light signal data at different powers are collected through a photoelectric detector, and the obtained data are recorded and processed to obtain electrical characteristic parameters of the detected semiconductor sample. The method is not influenced by the response time or bandwidth limitation of the photoelectric detector, the data processing is simple, and the measurement precision is high; the measuring device is simpler, and the equipment cost is low; the method is wide in application range, can be used for measuring quantum dot materials with deep energy level traps, and is particularly suitable for measuring quantum dot materials with more shallow energy level traps.

The invention provides a TOPCon solar cell, a preparation method thereof and a photovoltaic module. The TOPCon solar cell comprises a hole selective emitter layer arranged on a first main surface of an n-type silicon wafer and an electron selective passivation contact structure arranged on a second main surface of the silicon wafer, wherein the passivation contact structure comprises a tunneling oxide layer and an n + polycrystalline silicon layer; the first main surface and / or the second main surface are / is provided with a graphical opening area, and the graphical opening area comprises a passive film covering the surface of the silicon wafer and an anti-reflection film covering the surface of the passive film; and forming an undoped pyramid structure on the surface of the silicon wafer in the patterned opening region. According to the TOPCon solar cell, the absorption loss of infrared free carriers can be reduced, the film layer stress and the film explosion risk are relieved, and the process flexibility and adjustability are high.

The application provides a solar cell and a preparation method thereof. The solar cell comprises a silicon substrate having a first surface and a second surface arranged oppositely, the first surface comprising electrode regions and non-electrode regions arranged alternately; a first tunneling oxide layer, a first doped polysilicon layer, a second tunneling oxide layer and a second doped polysilicon layer arranged sequentially on the first surface and / or the second surface; wherein the first doped polysilicon layer is doped with a first dopant and a second dopant, and the second doped polysilicon layer is doped with the first dopant, and the doping concentration of the first dopant in the second doped polysilicon layer is greater than the doping concentration of the first dopant in the first doped polysilicon layer. The first doped polysilicon layer in the solar cell can achieve excellent passivation and significantly reduced free carrier absorption, and the second doped polysilicon layer can achieve rapid transport of carriers and excellent field passivation, which is helpful to improve the open-circuit voltage and the fill factor.

This invention provides a TOPCon battery structure with two polycrystalline silicon layers and its fabrication method, relating to the field of battery processing technology. The TOPCon battery structure includes a monocrystalline silicon wafer, with a diffusion layer, a passivation layer, a front antireflection layer, and a front metal electrode sequentially disposed on the front side of the monocrystalline silicon wafer, and a tunneling layer, a doped polycrystalline silicon layer, a back antireflection layer, and a back metal electrode sequentially disposed on the back side of the monocrystalline silicon wafer. The doped polycrystalline silicon layer includes a first doped polycrystalline silicon layer located on the back side and a second doped polycrystalline silicon layer located between the back metal electrode and the first doped polycrystalline silicon layer, wherein the doping concentration of the second doped polycrystalline silicon layer is greater than that of the first doped polycrystalline silicon layer. This invention overcomes the shortcomings of existing technologies, ensuring the thickness of the doped polycrystalline silicon in the metal contact area, preventing damage to the tunneling oxide layer during sintering, and reducing recombination current and contact resistance; simultaneously, it reduces photoparasitic absorption in the non-metallic region, especially reducing free carrier absorption.

The invention provides a TOPCon solar cell with a localized passivation contact structure, a manufacturing method of the TOPCon solar cell and a cell module. The TOPCon solar cell with the localized passivation contact structure comprises a cell silicon wafer; the polycrystalline silicon stack layer is arranged on the back surface of the battery silicon wafer; the dielectric layer is arranged between the polycrystalline silicon stack layer and the battery silicon wafer; the groove extends along the thickness direction of the TOPCon solar cell and penetrates through the polycrystalline silicon stack layer and the dielectric layer; the polycrystalline silicon stack layer is divided into at least one localization area, and the localization area comprises a first area and a second area surrounding the first area; in the TOPCon solar cell, the groove is located in the first region and / or the second region. According to the TOPCon solar cell, the absorption loss of infrared free carriers can be reduced, the stability of a passivation interface is improved, the film stress and the film explosion risk are relieved, and the local carrier collection capacity is enhanced.

The application discloses a high-refractive-index extended-cavity vertical-cavity surface-emitting laser, a preparation method and application thereof, and relates to the technical field of semiconductors. The application solves the problems of a large line width of an existing vertical-cavity surface-emitting laser and difficulty in controlling a narrow line width in the prior art. The laser comprises, from top to bottom, a top electrode, a p-type Bragg mirror group, an oxidation layer, an active region, an n-type extension layer, an n-type Bragg mirror group, a substrate and a bottom electrode, wherein the n-type extension layer is Al y Ga 1‑ y As, and y is 0.1-0.9. By arranging the n-type extension layer and setting the n-type extension layer to a specific material, resistance and free carrier absorption in the extension layer are inhibited, the effective cavity length of the laser is effectively increased, the resonant cavity length is increased, the output power is increased, the line width enhancement factor alpha is reduced, and the spectral line width is narrowed.

This invention discloses a vertical-cavity surface-emitting laser (VCSEL), comprising, from bottom to top, a substrate, a lower grating layer, an active layer, a contact layer, and an upper grating layer. The upper grating layer protrudes from the middle of the contact layer, and a first step is formed between the sidewall of the upper grating layer and the contact layer. The contact layer and the active layer protrude from the middle of the lower grating layer, and a second step is formed between the sidewall of the contact layer and the active layer and the lower grating layer. A p-type electrode is also provided on the contact layer, and a heat dissipation electrode is also provided on the p-type electrode, extending from the first step to the second step. This invention places the p-type electrode on the contact layer, thereby reducing the distance between the p-type electrode and the active layer, effectively reducing free carrier absorption and self-heating. Furthermore, the presence of a heat dissipation electrode on the p-type electrode further increases the contact surface between the heat dissipation electrode and the external environment, improving the heat dissipation performance of the VCSEL.

A potential difference measurement device (101) comprises: a light source (1); a semiconductor optical element (3) in which free carriers generated by the presence of charged particles absorb incident light incident from the light source (1), thereby reducing the intensity of emitted light that is emitted, relative to the intensity of the incident light; a detector (5) that detects the intensity of the emitted light; and a calculation unit (6) that calculates the intensity difference of the emitted light between before and after the reduction. The intensity difference varies according to the potential difference between outer space and a charged body (10) charged by the charged particles. The calculation unit (6) measures the potential difference by calculating the intensity difference in a state in which the semiconductor optical element (3) is disposed on the charged body (10) and the surface potential of the semiconductor optical element (3) is set to the same potential as the potential of the charged body (10) or to a potential having a predetermined potential difference with the potential of the charged body (10).

Disclosed herein are methods, structures, apparatus and devices for the termination of unused waveguide ports in planar photonic integrated circuits with doped waveguides such that free-carrier absorption therein may advantageously absorb any undesired optical power resulting in a significant reduction of stray light and resulting reflections.