非晶/微晶两相硅薄膜电池的计算机模拟

在对不同晶相比硅薄膜的实验研究的基础上，利用有效介质理论估算了这种两相材料的光吸 收系数、迁移率寿命乘积及带隙宽度等参量，计算机模拟了不同结晶比硅薄膜电池的伏安特 性及光谱响应；结果为随着本征层微晶成分的增多，电池的开路电压逐渐减小，短路电流逐 渐增大，本征层的最佳厚度逐渐增大，填充因子有降低的趋势，电池的效率随晶相比的增大 而减小. 电池的光谱响应曲线表明，随晶相比的增大电池的长波响应明显提高. 根据这些模 拟结果，分析讨论了在考虑Lambertian背反射的情况下，非晶/微晶叠层电池的底电池采用 晶相比为40％—50％的两相硅薄膜材料做本征层是最佳选择. 关键词： 两相硅薄膜 太阳能电池 计算机模拟

Computer simulation of a-Si:H/μc-Si:H diphasic silicon solar cells

Based on our experimental research on diphasic silicon films, the parameters suc h as absorption coefficient, mobility life- time product and bandgap were estima ted by means of effective-medium theory. And then computer simulation of a-Si:H/ μc-Si:H diphasic thin film solar cells was performed. It was shown that the mor e crystalline fraction in the diphasic silicon films, the higher short circuit d ensity, the lower open-circuit voltage and the lower efficiency. From the spectr al response, we can see that the response in long wave region was improved signi ficantly with increasing crystalline fraction in the silicon films. Taking Lamb ertian back refraction into account, the diphasic silicon films with 40%—50% cr ystalline fraction was considered to be the best intrinsic layer for the bottom solar cell in micromorph tandem.