Ozcan Can, Turkay Deniz, Yerci Selcuk
Opt Express. 2019 Apr 15;27(8):A339-A351. doi: 10.1364/OE.27.00A339.
An alternative structure to planar CdTe solar cells is realized by coating ZnO/CdS nanorods (NRs) with a CdTe layer. These structures are expected to achieve high-powered conversion efficiencies through enhanced light absorption and charge carrier collection. ZnO NR-based CdTe solar cell efficiencies; however, they have remained well below their planar counterparts, thus hindering NRs in CdTe solar cells' advantages. Here, we analyze the light trapping and carrier collection efficiencies in two types of ZnO NR-based CdTe solar cells through optical and electrical simulations. The buried CdTe solar cells are formed by completely filling the gaps in between ZnO/CdS NRs. This produces a maximum achievable photo-current of 27.4 mA/cm when 2000 nm-tall and 20̊-angularly-deviated NRs are used. A short-circuit current density of 27.3 mA/cm is achievable with the same geometry for 5 rods/μm-dense NRs when a moderate CdTe doping density and a CdS/CdTe surface velocity of 10 cm and 10 cm/s are used, respectively. We reveal the potential of buried CdTe solar cell for high-charge carrier collection and provide a design guideline in order to achieve high short-circuit current densities with ZnO NR-based CdTe solar cells.
通过用碲化镉（CdTe）层包覆氧化锌/硫化镉（ZnO/CdS）纳米棒（NRs）实现了一种与平面碲化镉太阳能电池不同的结构。这些结构有望通过增强光吸收和电荷载流子收集来实现高功率转换效率。然而，基于氧化锌纳米棒的碲化镉太阳能电池的效率仍远低于其平面同类电池，从而阻碍了碲化镉太阳能电池中纳米棒的优势。在此，我们通过光学和电学模拟分析了两种基于氧化锌纳米棒的碲化镉太阳能电池中的光捕获和载流子收集效率。掩埋式碲化镉太阳能电池是通过完全填充氧化锌/硫化镉纳米棒之间的间隙形成的。当使用2000纳米高且有20°角偏差的纳米棒时，可产生最大可达光电流27.4毫安/平方厘米。当分别使用适度的碲化镉掺杂密度以及10厘米/秒和10厘米/秒的硫化镉/碲化镉表面速度时，对于每微米5根密集纳米棒的相同几何结构，可实现27.3毫安/平方厘米的短路电流密度。我们揭示了掩埋式碲化镉太阳能电池在高电荷载流子收集方面的潜力，并提供了一种设计指南，以便在基于氧化锌纳米棒的碲化镉太阳能电池中实现高短路电流密度。
