Theoretical Calculation And Experimental Optimization Of Anitimony-basde Thin Film Solar Cells

Antimony-based thin film solar cells have gained rapid development due to their advantages such as simple preparation methods,rich raw materials,and stable photoelectric performance.Their photoelectric conversion efficiency has been continuously improved,currently exceeding10%.The preparation of antimony-based thin film solar cells with high environmental adaptability and high photoelectric conversion efficiency is the key to promoting their further industrialization.Based on this,this paper first uses numerical simulation methods to construct short-wave attenuation and long-wave attenuation spectra,and through reasonable optimization of antimony-based thin film batteries,seeks efficient antimony based solar cell structures that adapt to different lighting environments.The effects of absorbing layer thickness and carrier mobility on the performance of single junction Sb₂Se₃ solar cells under long and short wave attenuation spectra were studied.The results showed that when the absorbing layer thickness was 0.2μm.The photoelectric conversion efficiency of the battery under two weak light spectra differs greatly by 4.11%;When the thickness of the light absorbing layer is 2μm,the battery performance decreases due to the increase in carrier recombination.In addition,with the decrease of carrier mobility,the photoelectric conversion efficiency of the battery under the long wave attenuation spectrum decreases faster.Through dual modulation of thickness and carrier mobility,it is found that when the thickness of the Sb₂Se₃ light absorbing layer is higher than 0.5μm and the carrier mobility is greater than 1 cm²V^-1s^-1,Sb₂Se₃ solar cells have both good carrier generation and transport characteristics,enabling them to achieve high performance of more than 18%in PCE under both spectra.Then,by adjusting the spectral absorption range of the Sb₂(S_1-xSe_x)₃ solar cell through the selenium content,it was found that the device performance of the Sb₂(S_1-xSe_x)₃ solar cell under the long wave attenuation spectrum was significantly higher than the standard spectrum,and the optimal conversion efficiency could be achieved at 20%-40%selenium content.In the short-wave attenuation spectrum,the best performance of solar cells occurs when the selenium content is 60%.Therefore,under weak light conditions,the optimal selenium content of antimony-based solar cells needs to be determined through specific spectral characteristics.Secondly,this paper studied the spectral response characteristics of Sb₂S₃/Sb₂Se₃ double junction tandem solar cells under two attenuation spectra.It was found that under the short-wave attenuation spectrum,by increasing the thickness of the light-absorbing layer of the top and bottom cell,the utilization rate of spectral energy of the tandem cell continued to improve,and the efficiency continued to increase.In the long wave attenuation spectrum,the thin Sb₂S₃ layer can effectively utilize short wave light,and the optimal performance of tandem-cell under the different total thicknesses of light-absorbing layers remains at a high level.When the total thickness of the tandem cell is 2μm and the thickness of the Sb₂S₃ layer is between 0.5-1.2μm,the device can achieve a reasonable distribution of spectral energy between the two sub-cells under both attenuation spectra,allowing the efficiency of the tandem-cell to remain above 20%.Finally,because the longitudinal growth mode of（Sb₄Se₆）_n can improve the carrier transport efficiency and reduce the recombination probability,this paper studies the mechanism of preferential growth of Sb₂Se₃ thin films induced by different properties of Sn O₂ substrates by combining density functional theory calculations with experimental analysis.The binding energy between（Sb₄Se₆）₁ molecular chain and pure Sn O₂,Cu,and Cd doped Sn O₂ surfaces were calculated.The results showed that the maximum binding energy between（Sb₄Se₆）₁ molecular chain and Cd-doped Sn O₂ surfaces was-4.29 e V.Experimental results show that the antimony selenide thin film exhibits a significant longitudinal diffraction peak on the Sn O₂ thin film treated with Cd Cl₂ solution.At this time,the solar cell achieves a photoelectric conversion efficiency of 1.83%,significantly improving device performance compared to the efficiency of0.12%and 0.11%for untreated and Cu Cl₂ solution-treated devices.The results of calculations and experiments indicate that the growth and orientation regulation of antimony selenide on the substrate may be related to the strength of the interaction between the two.