Understanding the Electronic Structure and Optical Properties of Vacancy-Ordered Double Perovskite A₂BX₆ for Optoelectronic Applications

Abstract

Over the past few years, metal halide perovskite solar cells have made significant advances. Currently, the single-junction perovskite solar cells reach a conversion efficiency of 25.7%. Perovskite solar cells with a wide band gap can also be used as top absorber layers in multi-junction tandem solar cells. We examined the dynamical and thermal stability, electronic structure, and optical features of In2PtX6 (X = Cl, Br, and I) perovskites, utilizing first-principle calculations. The stability is predicted using phonon dispersion spectrum and ab initio molecular dynamics simulation and also through the convex hull approach. The lattice constants and the optimized volume show an increasing trend with changing halide ions. The band structures computed for In2PtCl6, In2PtBr6, and In2PtI6 indicate their semiconducting nature with band gap values of 2.06, 2.01, and 1.35 eV, respectively. Halogens p and Pt d orbitals, respectively, play a prominent role in the formation of states around valence band maximum and conduction band minimum. The compounds, namely, In2PtBr6 and In2PtI6, exhibit high dielectric constants and small carrier effective masses. Furthermore, we found that In2PtI6 reveals a maximum theoretical efficiency owing to its optimum band gap and high optical absorption and is comparable to MAPbI3 in the studied range. Our results suggest that In2PtX6 (X = Cl, Br, and I) are suitable materials for single-junction and top absorber layers in tandem solar cells.

Additive Engineering for Mixed Lead–Tin Narrow-Band-Gap Perovskite Solar Cells: Recent Advances and Perspectives

“…In addition, the BF 4 anion as a pseudohalide anion effectively decreased the lattice strain and stabilized the perovskite structure. The IMBF 4 145 In comparison to UiO-66, the electrondonating amino group of UiO-66-NH 2 interacted with uncoordinated Pb 2+ /Sn 2+ to achieve efficient defect passivation and inhibit defect-related carrier recombination. The UiO-66-NH 2 -modified normal PSCs exhibited a better PCE of 13.93% than the pristine (9.94%) and UiO-66-modified (10.17%) cells.…”

“…The progress and development of human society are closely related to the exploitation and high-efficiency utilization of energies. Thus, the potential energy forms (carriers) and advanced energy technologies have attracted increasing attention since the scientific, technological, and industrial revolutions. − As the main energy source nowadays, fossil fuels cannot be able to meet the ever-increasing energy demand in the future as a result of the non-renewable nature and low utilization efficiency. − Meanwhile, the excessive use of fossil fuels unavoidably produces a large number of greenhouse gases, leading to serious global climate change and environmental pollution. , In the context of the global era of the joint response to climate change and carbon neutrality, it is highly imperative to seek alternative renewable energies to replace fossil fuels. − Recently, solar energy has received increasing interests as a result of its abundance, cleanliness, and renewable nature . Generally, there are three main routes for the conversion and utilization of solar energy, including direct solar heating, photocatalytic water splitting, and photovoltaics. − Among them, photovoltaics (solar cells) that realize direct conversion from solar energy to electricity have achieved remarkable achievements recently.…”

Design potential and future prospects of lead-free halide perovskites in photovoltaic devices

“…239 The A 2 BX 6 structure can also be derived from the ABX 3 structure after removing one-half B cations of the [BX 6 ] cluster centre. 245 To maintain charge neutrality, cation B must be tetravalent. Alternatively, if a vacancy is created at the cation B-site of the double perovskite A 2 B 1+ B 3+ X 6 , an A 2 BX 6 double perovskite is formed (Fig.…”

Stability and efficiency improvement of perovskite solar cells by surface hydroxyl defect passivation of SnO2 layer with 4-fluorothiophenol

“…Perovskite solar cells (PSCs) have been intensively studied since the rst stable 9.7% efficient solid-state PSC reported in 2012, 1 which eventually led to a power conversion efficiency (PCE) of 25.7% 2 that surpassed the PCEs of conventional thin-lm technologies based on CIGS and CdTe. 3,4 High-efficiency PSCs reported are typically based on n-i-p structure, where an electron transport layer (ETL) is deposited on a transparent conductive oxide and a hole transport layer is formed on the perovskite layer. TiO 2 and SnO 2 have been widely used for ETLs.…”