Photovoltaic devices based on amorphous silicon/crystalline silicon (a-Si:H/c-Si) heterojunction interfaces hold the highest efficiency as of date in the class of silicon-based devices with efficiencies exceeding 26% and are regarded as a promising technology for large-scale terrestrial PV applications. The detailed understanding behind the operation of this type of device is crucial to improving and optimizing its performance. SHJ solar cells have primarily two main interfaces that play a major role in their operation: the transparent conductive oxide (TCO)/a-Si:H interface and the a-Si:H/c-Si heterojunction interface. In the work presented here, a detailed analytical description is provided for the impact of both interfaces on the performance of such devices and especially on the device fill factor (). It has been found that the TCO work function can dramatically impact the by introducing a series resistance element in addition to limiting the forward biased current under illumination causing the well-known S-shape characteristic in the I-V curve of such devices. On the other hand, it is shown that the thermionic emission barrier at the heterojunction interface can play a major role in introducing an added series resistance factor due to the intrinsic a-Si:H buffer layer that is usually introduced to improve surface passivation. Theoretical explanation on the role of both interfaces on device operation based on 1D device simulation is experimentally verified. The I-V characteristics of fabricated devices were compared to the curves produced by simulation, and the observed degradation in the of fabricated devices was explained in light of analytical findings from simulation.

中文翻译：

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硅异质结和TCO阻挡层在硅异质结太阳能电池运行中的作用：理论与实验的比较

基于非晶硅/晶体硅（a-Si：H / c-Si）异质结界面的光伏器件是迄今为止效率最高的硅基器件，其效率超过26％，被认为是一种有前途的技术大型地面光伏应用。对此类设备的操作进行详细的了解对于改善和优化其性能至关重要。SHJ太阳能电池主要有两个主要界面在其操作中起主要作用：透明导电氧化物（TCO）/ a-Si：H界面和a-Si：H / c-Si异质结界面。在此处介绍的工作中，提供了两个接口对此类设备的性能，尤其是对设备填充因子（）的影响的详细分析说明。业已发现，TCO功函数可通过引入串联电阻元件来极大地影响TCO功能，此外还限制了照明下的正向偏置电流，从而在此类器件的IV曲线中引起众所周知的S形特性。另一方面，由于通常引入本征a-Si：H缓冲层通常是为了改善表面钝化而引入的，因此表明异质结界面处的热电子发射势垒可以在引入附加串联电阻因子中起主要作用。通过实验验证了有关两个接口在基于一维设备仿真的设备操作中的作用的理论解释。将制成的器件的IV特性与通过仿真得出的曲线进行比较，并观察到了器件的退化。 根据仿真的分析结果解释了制造设备的制造过程。