Photovoltaic solar cells based on thin-film cadmium telluride (CdTe) have emerged as a potential contender in terms of efficiency in comparison to multi-crystalline silicon solar cell technology. The record efficiency presented in literature is reported to be as high as 22%. However, the theoretical approach suggests that the efficiency of up-to 25% can be achieved through these solar cells. The one of the main factors that affect the efficiency of the solar cells is the open circuit voltage (V_oc) and the maximum Voc for CdTe solar reported was about 600 mV. Thus, In order to increase the V_oc we have intentionally drifted the external voltage bias of 700 mV, 800 mV, 900 mV and 1000 mV to the active layer of CdTe based solar cell and see the physical impact of native defects in form of trapped charges that are actually responsible for limitation of lower open circuit voltage. For this, we have used the diagnostic technique known as Charge Deep Level Transient Spectroscopy (Q-DLTS) under dark and luminous conditions at different values of ambient temperatures and external bias potential. We have experimentally investigated that there exist high recombination trap centers located at 0.448 eV, 0.383 eV, 0.366 eV and 0.341 eV within the energy band gap of CdTe which hinder us to obtain the theoretical limits of V_oc.

与多晶硅太阳能电池技术相比，基于薄膜碲化镉（CdTe）的光伏太阳能电池已成为潜在的竞争者。据报道，文献记载的记录效率高达22％。但是，理论方法表明，通过这些太阳能电池可以实现高达25％的效率。影响太阳能电池效率的主要因素之一是开路电压（V _oc），据报道，CdTe太阳能的最大Voc约为600 mV。因此，为了增加V _oc我们有意将700 mV，800 mV，900 mV和1000 mV的外部电压偏置漂移至基于CdTe的太阳能电池的有源层，并以捕获电荷的形式看到了自然缺陷的物理影响，这些电荷实际上是限制了较低的开路电压。为此，我们使用了在黑暗和明亮条件下，在不同的环境温度和外部偏置电势下，称为电荷深层瞬态光谱学（Q-DLTS）的诊断技术。我们已经进行了实验研究，发现在CdTe的能带隙内存在高重组陷阱中心，分别位于0.448 eV，0.383 eV，0.366 eV和0.341 eV，这阻碍了我们获得V _oc的理论极限_。