Density of photoinduced free carriers in perovskite thin films via purely optical detection. Issue 13 (15th March 2017)

• Record Type: Journal Article
• Authors: Li, Yu; Wang, Wei; Wang, Xiangyuan; Wang, Shufeng; Shi, Yantao; Gong, Qihuang
• Is Part Of: Journal of materials chemistry. Volume 5:Issue 13(2017)
• Page Start: 3283
• Page End: 3287
• Publication Date: 2017-03-15
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c7tc00102a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Real free carrier densities of organolead perovskites and their behaviors under working condition were retrieved regardless of ionic interference. Abstract : The great strides of perovskite-based photovoltaic devices galvanize an increasing number of material studies. We revealed the photoinduced steady-state free carrier densities of perovskite films through a purely optical detection method. The method avoided the possible interference from strong ionic conductivity within perovskite materials. The densities were measured at the order of 10 15 cm −3 and 10 16 cm −3 for CH3 NH3 PbI3 films without and with chlorine introduction, respectively. Long free carrier lifetimes were figured out according to the densities. The densities were found to increase, as observed from the illumination, following a sublinear power law. This indicates sub-bandgap trapping states involved in the charge accumulation mechanism. In addition, the densities presented an abnormal temperature sensitivity revealing a thermally activated recombination channel above ∼240 K.