Faridi Ahmed Waseem, Imran Muhammad, Tariq Ghulam Hasnain, Ullah Sana, Noor Syed Farhan, Ansar Sabah, Sher Farooq
Department of Physics, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan 64200, Pakistan.
Department of Mechanical Engineering, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan 64200, Pakistan.
Ind Eng Chem Res. 2022 Apr 25;62(11):4494-4502. doi: 10.1021/acs.iecr.2c00416. eCollection 2023 Mar 22.
Inorganic perovskite materials are possible candidates for conversion of solar energy to electrical energy due to their high absorption coefficient. Perovskite solar cells (PSCs) introduced a new type of device structure that has attention due to better efficiencies and interest in PSCs that has been increasing in recent years. Halide perovskite materials such as CsPbIBr show remarkable optical and structural performance with their better physical properties. Perovskite solar cells are a possible candidate to replace conventional silicon solar panels. In the present study, CsPbIBr perovskite materials' thin films were prepared for light-absorbing application. Five thin films were deposited on the glass substrates by subsequent spin-coating of CsI and PbBr solutions, subsequently annealed at different temperature values (as-deposited, 100, 150, 200 and 250 °C) to get CsPbIBr thin films with a better crystal structure. Structural characterizations were made by using X-ray diffraction. CsPbIBr thin films were found to be polycrystalline in nature. With increasing annealing temperature, the crystallinity was improved, and the crystalline size was increased. Optical properties were studied by using transmission data, and by increasing annealing temperature, a small variation in optical band gap energy was observed in the range of 1.70-1.83 eV. The conductivity of CsPbIBr thin films was determined by a hot probe technique and was found to have little fluctuating response toward p-type conductivity, which may be due to intrinsic defects or presence of CsI phase, but a stable intrinsic nature was observed. The obtained physical properties of CsPbIBr thin films suggest them as a suitable candidate as a light-harvesting layer. These thin films could be an especially good partner with Si or other lower band gap energy materials in tandem solar cells (TSC). CsPbIBr material will harvest light having energy of ∼1.7 eV or higher, while a lower energy part of the solar spectrum will be absorbed in the partner part of the TSC.
无机钙钛矿材料因其高吸收系数而有望成为将太阳能转化为电能的候选材料。钙钛矿太阳能电池（PSC）引入了一种新型器件结构，由于其具有更高的效率，近年来对PSC的关注度不断提高。卤化物钙钛矿材料如CsPbIBr具有出色的光学和结构性能以及更好的物理性质。钙钛矿太阳能电池有望取代传统的硅太阳能板。在本研究中，制备了CsPbIBr钙钛矿材料薄膜用于光吸收应用。通过依次旋涂CsI和PbBr溶液在玻璃基板上沉积五层薄膜，随后在不同温度值（原样、100、150、200和250°C）下退火，以获得具有更好晶体结构的CsPbIBr薄膜。使用X射线衍射进行结构表征。发现CsPbIBr薄膜本质上是多晶的。随着退火温度的升高，结晶度提高，晶体尺寸增大。利用透射数据研究光学性质，随着退火温度的升高，观察到光学带隙能量在1.70 - 1.83 eV范围内有微小变化。通过热探针技术测定CsPbIBr薄膜的电导率，发现其对p型导电性的响应波动较小，这可能是由于固有缺陷或CsI相的存在，但观察到其具有稳定的本征性质。所获得的CsPbIBr薄膜的物理性质表明它们是作为光捕获层的合适候选材料。这些薄膜在串联太阳能电池（TSC）中可能特别适合与硅或其他带隙能量较低的材料搭配。CsPbIBr材料将捕获能量约为1.7 eV或更高的光，而太阳光谱中能量较低的部分将被TSC的另一部分吸收。
