期刊
ACS APPLIED MATERIALS & INTERFACES
卷 10, 期 4, 页码 3750-3760出版社
AMER CHEMICAL SOC
DOI: 10.1021/acsami.7b14039
关键词
perovskites; cesium perovskites; inorganic perovskites; stability; solar cells; photovoltaics
资金
- EPSRC Centre for Doctoral Training in New and Sustainable Photovoltaics CDT-PV [EP/L01551X/1]
- EPSRC Centre for Doctoral Training in New and Sustainable Photovoltaics CDT-PV [EP/L01551X/1]
- Engineering and Physical Sciences Research Council [1511067, 1521904] Funding Source: researchfish
In this manuscript, the inorganic perovskite CsPbI2Br is investigated as a photovoltaic material that offers higher stability than the organic inorganic hybrid perovskite materials. It is demonstrated that CsPbI2Br does not irreversibly degrade to its component salts as in the case of methyl ammonium lead iodide but instead is induced (by water vapor) to transform from its metastable brown cubic (1.92 eV band gap) phase to a yellow phase having a higher band gap (2.85 eV). This is easily reversed by heating to 350 degrees C in a dry environment. Similarly, exposure of unencapsulated photovoltaic devices to water vapor causes current (J(SC)) loss as the absorber transforms to its more transparent (yellow) form, but this is also reversible by moderate heating, with over 100% recovery of the original device performance. NMR and thermal analysis show that the high band gap yellow phase does not contain detectable levels of water, implying that water induces the transformation but is not incorporated as a major component. Performances of devices with best efficiencies of 9.08% (V-OC = 1.05 V, J(SC) = 12.7 mA cm(-2) and FF = 68.4%) using a device structure comprising glass/ITO/c-TiO2/CsPbI2Br/Spiro-OMeTAD/Au are presented, and further results demonstrating the dependence of the performance on the preparation temperature of the solution processed CsPbI2Br films are shown. We conclude that encapsulation of CsPbI2Br to exclude water vapor should be sufficient to stabilize the cubic brown phase, making the material of interest for use in practical PV devices.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据