1.7 MeV电子辐照对CdTe太阳电池电流传输特性影响的图谱分析

摘要

研究了1.7 MeV的电子辐照对具有Anti-radiation glass/ITO/ZnO/CdS/CdTe/ZnTe/ZnTe∶Cu/Ni结构的碲化镉多晶薄膜太阳电池器件性能的影响。抗辐照玻璃的使用，有效防止了普通玻璃受辐照后性能变化对测试结果的影响。利用光、暗I-V ，C-V ，QE ，AS等测试手段，分析了包括开路电压、短路电流、转换效率在内的电池性能。通过对比研究暗电流密度、分析了辐照对电池电流传输特性的影响。辐照后短路电流下降很大，电池效率明显降低。反向饱和电流密度有所增加，表明太阳电池的pn结特性受到损伤，而二极管理想因子几乎不变，说明太阳电池电流的输运机制未发生了变化。量子效率曲线证明是由于太阳电池结区损伤影响了光生载流子的收集。辐照使载流子浓度下降为原来的40.6％。导纳谱研究最终发生辐照会引入Cd2＋缺陷能级，其位置为 Et -Ev ＝（0.58±0.02）eV ，俘获截面为1.78×10-16 cm2，表明辐照会影响光生载流子的产生，增加了载流子复合的概率，使得反向暗电流增大，最终导致电池的短路电流衰减。%The effects of device performance of 1.7 MeV electron irradiation on cadmium telluride polycrystal-line thin film solar cells with the structure of anti-radiation glass/ITO/ZnO/CdS/CdTe/ZnTe/ZnTe∶Cu/Ni have been studied .Light and dark I-V characteristics ,dark C-V characteristics ,quantum efficiency (QE) ,ad-mittance spectrum (AS) and other testing methods were used to analyze cells performance such as the open-cir-cuit voltage (Voc) ,short-circuit current (Isc) ,fill factor (FF) and conversion efficiency (η) .It was explored to find out the effects of irradiation on the current transfer characteristic of solar cells combined with the dark current density (Jo) ,diode ideal factor (A) ,quantum efficiency ,carrier concentration and the depletion layer width .The decline in short-circuit current was very large and the efficiency of solar cells decreased obviously after irradiation .Reverse saturation current density increased ,which indicates that p-n junction characteristics of solar cells were damaged ,and diode ideal factor was almost the same ,so current transport mechanism of so-lar cells has not changed .Quantum efficiency curves proved that the damage of solar cells’ p-n junction influ-enced the collection of photo-generated carriers .Irradiation made carrier concentration reduce to 40.6% .The analyses have shown that .A new defect was induced by electron irradiation ,whose position is close to 0.58 eV above the valence band in the forbidden band ,and capture cross section is 1.78 × 10-16 cm2 .These results indicate that irradiation influences the generation of photo-generated carriers ,increases the risk of the carrier recombination and the reverse dark current ,and eventually makes the short-circuit current of solar cells decay .