TY - JOUR

T1 - Modulating optoelectronic properties of organo-metal halide perovskites with unsaturated heterocyclic cations via ring substitution

AU - Kevorkyants, R.

AU - Bahnemann, Detlef

AU - Emeline, Alexei V.

N1 - Funding Information: The authors acknowledge St. Petersburg State University's research grant (Pure ID 39054581 ). The authors also thank the Center for Computational Resources of St. Petersburg State University (Peterhof campus) for the provided CPU time.

PY - 2019/12

Y1 - 2019/12

N2 - We propose a ring substitution as a method of modulation of optoelectronic properties of organo-metal halide perovskites containing unsaturated heterocyclic cations. Periodic DFT calculations of tin trichloride perovskites with arizinium cation and its derivatives show that an introduction of the electron-withdrawing –C[tbnd]N and –F groups into azirinium ring stabilizes the materials' CBs formed from antibonding molecular π-orbitals of the ring. This leads to a decrease of the perovskite bandgaps as compared to that of the parent arizinium tin trichloride (1.06 eV). The effect of the electron-donating groups –CH 3 and –NH 2 on the materials’ CBs and bandgaps is opposite. The predicted bandgaps of the four perovskites cover the energy range of [0.52:1.93] eV. A combination of both electronic effects in one ring substituent allows for a finer tuning of the perovskite optoelectronic properties that is exemplified by fluorinated methylarizinium tin trichlorides. Bandgaps of these materials vary from 1.86 eV (R = -CH 3) to 1.17 eV (R = -CF 3). Thus, a ring substitution in unsaturated heterocyclic cations of organo-metal halide perovskites paves a way to modulating their optoelectronic properties in a wide energy range.

AB - We propose a ring substitution as a method of modulation of optoelectronic properties of organo-metal halide perovskites containing unsaturated heterocyclic cations. Periodic DFT calculations of tin trichloride perovskites with arizinium cation and its derivatives show that an introduction of the electron-withdrawing –C[tbnd]N and –F groups into azirinium ring stabilizes the materials' CBs formed from antibonding molecular π-orbitals of the ring. This leads to a decrease of the perovskite bandgaps as compared to that of the parent arizinium tin trichloride (1.06 eV). The effect of the electron-donating groups –CH 3 and –NH 2 on the materials’ CBs and bandgaps is opposite. The predicted bandgaps of the four perovskites cover the energy range of [0.52:1.93] eV. A combination of both electronic effects in one ring substituent allows for a finer tuning of the perovskite optoelectronic properties that is exemplified by fluorinated methylarizinium tin trichlorides. Bandgaps of these materials vary from 1.86 eV (R = -CH 3) to 1.17 eV (R = -CF 3). Thus, a ring substitution in unsaturated heterocyclic cations of organo-metal halide perovskites paves a way to modulating their optoelectronic properties in a wide energy range.

KW - DFT

KW - Electronic properties

KW - Optical absorption

KW - Organo-metal halide perovskites

UR - http://www.scopus.com/inward/record.url?scp=85068594021&partnerID=8YFLogxK

U2 - 10.1016/j.jpcs.2019.109078

DO - 10.1016/j.jpcs.2019.109078

M3 - Article

VL - 135

JO - Journal of Physics and Chemistry of Solids

JF - Journal of Physics and Chemistry of Solids

SN - 0022-3697

M1 - 109078

ER -