Dear Researchers,
I hope you all will be in good health. I am writing this to request for your guidance. I am working on the fabrication of low bandgap Pb-Sn mixed perovskite with exact composition (FA0.7MA0.3Pb0.7Sn0.3I3). To study optical properties, I have run UV-vis spectroscopy and Photoluminescence spectroscopy. Optical bandgap was estimated to be around Eg=1.30 eV with a very vague absorption spectra due to ready oxidation of tin as shown in the graph. However, PL emission spectrum revealed various peaks from 885 nm to 1000 nm which is difficult to comprehend for me in comparison to absorption spectrum. I am looking for answers to the following questions?
1: Firstly, What could be the reason for the multiple peaks in emission spectrum?
2: Secondly, which peak in emission spectrum could be related to the absorbance spectra edge?
3: Thirdly, What could be the possible reason for the disparity in absorbance spectrum and relevant emission peak in Photoluminescence spectra?
I am very thankful to you and looking forward to your comments!
Best Wishes,
Abdul Sattar
Can you run an Excitation spectrum? I am not so familiar with this material, but I presume the emission is from localised trap, maybe defect states. These can be populated by relaxations of electrons excited across the interband transition. Comparison of the excitation spectrum and absorbance spectrum may tell you more about where these states lie, Increasing temperature may tell you about the activated released of trapped electrons back to the band
- Badges
- Science topic