No abstract

In this work, planar inorganic perovskite solar cells (PSCs) with the simple structure of glass/ITO/SnO2/CsPbI2Br/C have been fabricated.

Carbon-based inorganic perovskite solar cells (C-PSCs) have attracted intensive attention owing to their low cost and superior thermal stability. However, the bulk defects in perovskites and interfacial energy level mismatch seriously undermine their performance. To overcome these issues, a multifunctional dualinterface engineering is proposed with a focus on low-temperature CsPbI 2 Br C-PSCs, where the potassium trifluoroacetate (KTFA) and the 4-trifluorophenyl methylammonium bromide (CF 3 PMABr) are introduced beneath and on top of the perovskite layer, respectively. It is found that TFAions locate at the SnO 2 /CsPbI 2 Br interface, whereas a small amount of K + ions diffuse into perovskite lattice to participate in nucleation and crystallization, resulting in more favored interfacial energy level alignment, improved film quality, passivated interfacial defects, released interfacial strain, as well as suppressed charge recombination and ion migration. Meanwhile, the CF 3 PMABr passivates I/Br vacancies and forms 2D perovskite capping layer to facilitate hole extraction at the CsPbI 2 Br/carbon interface. As a result, a remarkable power conversion efficiency (PCE) of 14.05% with an open-circuit voltage of 1.273 V is achieved. To the best of the authors' knowledge, it is currently the highest PCE reported for low-temperature CsPbI 2 Br C-PSCs. Furthermore, the nonencapsulated device exhibits improved moisture, thermal, and illumination stability in ambient air.

Hybrid photovoltaic devices based on poly(3-hexylthiophene) (P3HT) and an ordered electrospun ZnO nanofibrous network have been investigated. The diameters of the ZnO nanofibers have been controlled within 30-150 nm. The performance of the P3HT/ZnO hybrid solar cell is dependent on fabrication conditions, especially the thickness of the nanofibrous film. It has been found that the lifetime of carriers is lower in the device consisting of thicker ZnO nanofibrous films due to the higher density of surface traps in the ZnO nanofibers. The device with optimum fabrication conditions exhibits a power conversion efficiency of 0.51%.