基于NiO空穴传输层的CH_3NH_3PbI_3钙钛矿太阳能电池的光伏特性

Photovoltaic characteristics of organic-inorganic hybrid perovskite CH_3NH_3PbI_3 solar cells with NiO hole transport layer

从2009年至今,基于卤族元素的有机-无机杂化钙钛矿薄膜太阳能电池由于简单的制备工艺和优良的光电转化效率,成为有望替代传统硅基太阳能电池的一种新型太阳能电池,由于其通常采用价格昂贵的有机空穴/电子传输层材料,所以虽然可获得较高的光电转化效率,但生产成本较高.本文选用价格低廉性质稳定的NiO为空穴传输层材料,利用旋涂热解法在导电ITO玻璃上制备平整致密的NiO薄膜,然后采用两步溶液法,在其上制备平均粒径约为150 nm的CH_3NH_3PbI_3吸光层,最后组装成ITO/NiO/CH_3NH_3PbI_3/PCBM/Ag平面倒置异质结型电池单元.本文对比研究了不同退火温度制备NiO薄膜的表面形貌和晶体结构,以及制备的电池单元的光伏性能.本文对比实验结果表明, 500°C退火处理的NiO薄膜最平整致密,以其为空穴传输层的未封装电池单元在大气环境中进行模拟太阳光辐照测试,可获得7.63%的光电转化效率和>1 V的开路电压,优于类似条件下制备的以NiO为空穴传输层的有机-无机杂化钙钛矿太阳能电池.

Since it was firstly reported in 2009, organic-inorganic hybrid perovskite solar cells based on halide elements have been one of promising new-type solar cells in replacement of traditional silicon-based solar cells due to their simple fabrication technology and high power conversion efficiency(PCE). However, in order to guarantee high PCE, they usually need expensive organic hole/electron transport materials, which is not conducive to cost reduction. In this paper,we choose NiO, one of cheap and stable inorganic oxide materials, as the hole transport material. 40 nm-thick NiO film is firstly deposited on ITO-covered glasses by using spin-coating method, then 250 nm-thick CH3NH3PbI3 films with an average grain size of about 150 nm is deposited on it by using two-step solution method under optimized conditions.After covering it with a 50 nm-thick PCBM film and 150 nm-thick Ag top electrodes, an inverted-planar-structure of solar cell based on ITO/NiO/CH3NH3PbI3/PCBM/Ag is obtained. Surface morphology and crystal structure of NiO films annealed at different temperatures has been studied, as well as photovoltaic properties of solar cells fabricated.Comparative experimental results reveal that the 500°C-annealed NiO film is dense, and smooth with a relatively good crystallinity. Under simulated solar radiation in atmosphere condition, the unsealed solar cell with the 500°C-annealed NiO hole transport layer exhibits a PCE of -7.63% and an open-circuit voltage Voc of >1 V. This Voc value is higher than that of other organic-inorganic hybrid perovskite solar cells with NiO hole transport layer fabricated under similar condition.