Rahman Mohammad, Boschloo Gerrit, Hagfeldt Anders, Edvinsson Tomas
Department of Engineering Sciences, Division of Solid State Physics, Angstrom Laboratory, Uppsala University, Uppsala, 751 21, Sweden.
Department of Chemistry, Angstrom Laboratory, Uppsala University, Uppsala, 751 20, Sweden.
Adv Mater. 2020 Jul;32(26):e1905653. doi: 10.1002/adma.201905653. Epub 2020 May 19.
Considering the natural abundance, the optoelectronic properties, and the electricity production cost, iron pyrite (FeS ) has a strong appeal as a solar cell material. The maximum conversion efficiency of FeS solar cells demonstrated to date, however, is below 3%, which is significantly below the theoretical efficiency limit of 25%. This poor conversion efficiency is mainly the result of the poor photovoltage, which has never exceeded 0.2 V with a device having appreciable photocurrent. Several studies have explored the origin of the low photovoltage in FeS solar cells, and have improved understanding of the photovoltage loss mechanisms. Fermi level pinning, surface inversion, ionization of bulk donor states, and photocarrier loss have been suggested as the underlying reasons for the photovoltage loss in FeS . Given the past and more recent scientific data, together with contradictory results to some extent, it is timely to discuss these mechanisms to give an updated view of the present status and remaining challenges. Herein, the current understanding of the origin of low photovoltage in FeS solar cells is critically reviewed, preceded by a succinct discussion on the electronic structure and optoelectronic properties. Finally, suggestions of a few research directions are also presented.
考虑到自然丰度、光电特性以及发电成本，黄铁矿（FeS₂）作为一种太阳能电池材料具有很强的吸引力。然而，迄今为止所展示的FeS₂太阳能电池的最大转换效率低于3%，这显著低于25%的理论效率极限。这种较差的转换效率主要是光电压较低的结果，对于具有可观光电流的器件，其光电压从未超过0.2V。多项研究探讨了FeS₂太阳能电池中低光电压的起源，并增进了对光电压损失机制的理解。费米能级钉扎、表面反转、体施主态电离以及光载流子损失被认为是FeS₂中光电压损失的潜在原因。鉴于过去和最近的科学数据，以及在一定程度上相互矛盾的结果，适时地讨论这些机制，以给出关于当前现状和剩余挑战的最新观点。在此，对FeS₂太阳能电池中低光电压起源的当前理解进行了批判性综述，在此之前先对电子结构和光电特性进行了简要讨论。最后，还提出了一些研究方向的建议。
