title: Band Gap Tuning of CH₃NH₃Pb(Br(1-x)Clx)₃ Hybrid Perovskite for Blue Electroluminescence.
abstract: We report on the structural, morphological and optical properties of AB(Br(1-x)Cl(x))3 (where, A = CH3NH3(+), B = Pb(2+) 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.
authors.forename: Naresh K
authors.initials: NK
authors.lastname: Kumawat
authors.forename: Amrita
authors.initials: A
authors.lastname: Dey
authors.forename: Aravindh
authors.initials: A
authors.lastname: Kumar
authors.forename: Sreelekha P
authors.initials: SP
authors.lastname: Gopinathan
authors.forename: K L
authors.initials: KL
authors.lastname: Narasimhan
authors.forename: Dinesh
authors.initials: D
authors.lastname: Kabra
keywords: Blue-PeLED; Bowing parameter; Sommerfield factor; Urbach energy; bandgap tuning; perovskite