Murshed Rubaiya, Bansal Shubhra
Department of Mechanical Engineering, Howard R. Hughes College of Engineering, University of Nevada, Las Vegas, NV 89154, USA.
Materials (Basel). 2022 Jan 25;15(3):899. doi: 10.3390/ma15030899.
Halide perovskite solar cells (HPSCs) are promising photovoltaic materials due to their excellent optoelectronic properties, low cost, and high efficiency. Here, we demonstrate atmospheric solution processing and stability of cesium tin-lead triiodide (CsSnPbI) thin films for solar cell applications. The effect of additives, such as pyrazine and guanidinium thiocyanate (GuaSCN), on bandgap, film morphology, structure, and stability is investigated. Our results indicate the formation of a wide bandgap (>2 eV) structure with a mixed phase of tin oxide (SnO) and Cs(Sn, Pb)I. The addition of pyrazine decreases the intensity of SnO peaks, but the bandgap does not change much. With the addition of GuaSCN, the bandgap of the films reduces to 1.5 eV, and a dendritic structure of Cs(Sn, Pb)I is observed. GuaSCN addition also reduces the oxygen content in the films. To enable uniform film crystallization, cesium chloride (CsCl) and dimethyl sulfoxide (DMSO) additives are used in the precursor. Both CsCl and DMSO suppress dendrite formation with the latter resulting in uniform polycrystalline films with a bandgap of 1.5 eV. Heat and light soaking (HLS) stability tests at 65 °C and 1 sun for 100 h show all film types are stable with temperature but result in phase segregation with light exposure.
卤化物钙钛矿太阳能电池（HPSC）因其优异的光电性能、低成本和高效率而成为有前景的光伏材料。在此，我们展示了用于太阳能电池应用的铯锡铅三碘化物（CsSnPbI）薄膜的大气溶液处理及稳定性。研究了吡嗪和硫氰酸胍（GuaSCN）等添加剂对带隙、薄膜形态、结构和稳定性的影响。我们的结果表明形成了具有氧化锡（SnO）和Cs（Sn，Pb）I混合相的宽带隙（>2 eV）结构。吡嗪的添加降低了SnO峰的强度，但带隙变化不大。添加GuaSCN后，薄膜的带隙降至1.5 eV，并观察到Cs（Sn，Pb）I的树枝状结构。添加GuaSCN还降低了薄膜中的氧含量。为实现均匀的薄膜结晶，在前驱体中使用了氯化铯（CsCl）和二甲基亚砜（DMSO）添加剂。CsCl和DMSO都抑制了树枝状结构的形成，后者形成了带隙为1.5 eV的均匀多晶薄膜。在65°C和1个太阳光照下进行100小时的热光浸泡（HLS）稳定性测试表明，所有薄膜类型在温度方面都很稳定，但在光照下会发生相分离。
