title: Enhancing Intrinsic Stability of Hybrid Perovskite Solar Cell by Strong, yet Balanced, Electronic Coupling.
abstract: In the past few years, the meteoric development of hybrid organic-inorganic perovskite solar cells (PSC) astonished the community. The efficiency has already reached the level needed for commercialization; however, the instability hinders its deployment on the market. Here, we report a mechanism to chemically stabilize PSC absorbers. We propose to replace the widely used methylammonium cation (CH3NH3(+)) by alternative molecular cations allowing an enhanced electronic coupling between the cation and the PbI6 octahedra while maintaining the band gap energy within the suitable range for solar cells. The mechanism exploits establishing a balance between the electronegativity of the materials' constituents and the resulting ionic electrostatic interactions. The calculations demonstrate the concept of enhancing the electronic coupling, and hence the stability, by exploring the stabilizing features of CH3PH3(+), CH3SH2(+), and SH3(+) cations, among several other possible candidates. Chemical stability enhancement hence results from a strong, yet balanced, electronic coupling between the cation and the halides in the octahedron. This shall unlock the hindering instability problem for PSCs and allow them to hit the market as a serious low-cost competitor to silicon based solar cell technologies.
authors.affiliation: Qatar Environment and Energy research Institute (QEERI), Hamad Bin Khalifa University, Doha, Qatar.
authors.forename: Fedwa
authors.initials: F
authors.lastname: El-Mellouhi
authors.affiliation: Qatar Environment and Energy research Institute (QEERI), Hamad Bin Khalifa University, Doha, Qatar.
authors.forename: El Tayeb
authors.initials: el T
authors.lastname: Bentria
authors.affiliation: Qatar Environment and Energy research Institute (QEERI), Hamad Bin Khalifa University, Doha, Qatar.
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Rashkeev
authors.affiliation: Qatar Environment and Energy research Institute (QEERI), Hamad Bin Khalifa University, Doha, Qatar.|College of Science and Engineering, Hamad Bin Khalifa University, Doha, Qatar.|Department of Chemistry, Physics, and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Sabre
authors.initials: S
authors.lastname: Kais
authors.affiliation: Qatar Environment and Energy research Institute (QEERI), Hamad Bin Khalifa University, Doha, Qatar.|College of Science and Engineering, Hamad Bin Khalifa University, Doha, Qatar.
authors.forename: Fahhad H
authors.initials: FH
authors.lastname: Alharbi