Band Gap Tuning of CH3NH3Pb(Br1鈥?i>xClx)3 Hybrid Perovskite for Blue Electroluminescence

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• 作者：Naresh K. Kumawat ; Amrita Dey ; Aravindh Kumar ; Sreelekha P. Gopinathan ; K. L. Narasimhan ; Dinesh Kabra
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：June 24, 2015
• 年：2015
• 卷：7
• 期：24
• 页码：13119-13124
• 全文大小：383K
• ISSN：1944-8252

文摘

We report on the structural, morphological and optical properties of AB(Br_1鈥?i>xCl_x)₃ (where, A = CH₃NH₃⁺, B = Pb²⁺ and x = 0 to 1) perovskite semiconductor and their successful demonstration in green and blue emissive perovskite light emitting diodes at room temperature. The bandgap of perovskite thin film is tuned from 2.42 to 3.16 eV. The onset of optical absorption is dominated by excitonic effects. The coulomb field of the exciton influences the absorption at the band edge. Hence, it is necessary to explicitly account for the enhancement of the absorption through the Sommerfield factor. This enables us to correctly extract the exciton binding energy and the electronic bandgap. We also show that the lattice constant varies linearly with the fractional chlorine content satisfying Vegards law.