低速p/i界面缓冲层对高速沉积微晶硅太阳电池性能的影响

在采用高压高功率的甚高频等离子体增强化学气相沉积(VHF-PECVD)技术高速沉积微晶硅(μc-Si：H)太阳电池过程中，产生的高能离子对薄膜表面的轰击作用会降低薄膜质量和破坏p型掺杂层(p层)与本征层(i层)之间的界面特性.针对该问题提出在电池中引入低速沉积的p/i界面层的方法，即在p层上先低速沉积一薄层本征μc-Si：H薄膜，然后再高速沉积本征μc-Si：H薄膜.实验结果表明，引入低速方法沉积的界面层有效地提高了p/i界面特性和i层微结构的纵向均匀性，而随界面层厚度的增加，i层中的缺陷态先降低后增加， 关键词： μc-Si：H太阳电池 甚高频等离子体增强化学气相沉积 p/i界面层

Influence of low rate p/i interface layer on the performance of high growth rate microcrystalline silicon solar cells

In the process of the high growth rate μc-Si：H film deposited by very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD)， the high energy ion impinging on the growing surface could deteriorate the device performance. Incorporation of a low growth rate intrinsic μc-Si：H p/i buffer layer was advanced in this paper. The results show that the introduced low growth rate buffer layer could improve the characteristics of p/i interface and the vertical uniformity of the intrinsic layer. It was found that the defects in intrinsic layer first decreased and then increased with increasing thickness of the buffer layer. These results led to an optimal thickness for the buffer layers. The efficiency of solar cells was increased about 1% when the thickness was optimized. As a result， the efficiency of 8.11% has been achieved at an i-layer deposition rate of 8.5nm/s.