Understanding what limits the voltage of polycrystalline CdSeTe solar cells
Understanding what limits the voltage of polycrystalline CdSeTe solar cells
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DOI：
10.1038/s41560-022-00985-z
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发表时间：
2022-03-03
期刊：
影响因子：
56.7
通讯作者：
Holman, Zachary C.
中科院分区：
文献类型：
--
作者：
Onno, Arthur;Reich, Carey;Holman, Zachary C.
多晶硒化镉(CdSeTe)太阳电池中电压缺陷的来源尚不清楚。在这里，我们使用光致发光技术，包括外部辐射效率(ERE)测量，对科罗拉多州立大学和First Solar制造的最先进的CdSeTe器件进行了全面的电压损失分析。更具体地说，我们报告了用不同掺杂种类、掺杂浓度和背接触制备的部分和完全成品电池的热力学电压极限V-oc、V-理想、内部电压IV(Oc)和外部电压V-oc。科罗拉多州立大学生产的掺砷氧化铝钝化电池具有非常高的ERE(>；1%)-转化为970 mV以上的IV(Oc)-但背接选择性较差。另一方面，First Solar的砷掺杂器件表现出几乎完美的载流子选择性(V-oc=IV(Oc))，导致V-oc超过840 mV，并且受到器件各部分复合的限制。因此，开发既钝化又具有选择性的接触结构并结合高发光吸收材料是降低电压损失的关键。碲化硒镉太阳能电池的开路电压赤字通常高于其他光伏技术，但原因尚不清楚。现在，Onno等人。使用光致发光技术来分解掺杂和背触点对电压损失的影响。
The origin of voltage deficits in polycrystalline cadmium selenide telluride (CdSeTe) solar cells is unclear. Here, we present a comprehensive voltage loss analysis performed on state-of-the-art CdSeTe devices-fabricated at Colorado State University and First Solar-using photoluminescence techniques, including external radiative efficiency (ERE) measurements. More specifically, we report the thermodynamic voltage limit V-oc,V-ideal, internal voltage iV(oc) and external voltage V-oc of partially and fully finished cells fabricated with different dopant species, dopant concentrations and back contacts. Arsenic-doped aluminium-oxide-passivated cells made at Colorado State University present remarkably high ERE (>1%)-translating into iV(oc) above 970 mV-but suffer from poor back-contact selectivity. On the other hand, arsenic-doped devices from First Solar present almost perfect carrier selectivity (V-oc = iV(oc)), leading to V-oc above 840 mV, and are limited by recombination in various parts of the device. Thus, development of contact structures that are both passivating and selective in combination with highly luminescent absorbers is key to reducing voltage losses.The open-circuit-voltage deficit of cadmium selenide telluride solar cells is typically higher than that of other photovoltaic technologies yet the reasons are unclear. Now, Onno et al. use photoluminescence techniques to break down the contributions of dopants and back contacts to voltage losses.