Titanium‐Based Vacancy‐Ordered Double Halide Family in Perovskite Solar Cells

Abstract

The toxicity and stability risk of perovskite structured materials have raised concerns in respective to utilization as a solar energy conversion material. The most common perovskite structured material is lead (Pb)-based, which is an element that is knowingly toxic to humans and the environment. Although the stability issue has been well allayed with several optimizations, the ruinous Pb remains a future challenge for perovskite solar cells. Compositional and structural derivatives of the perovskite family, specifically vacancy-ordered double halide perovskites (DHPs), have attracted the attention of researchers in terms of efficiency and toxicity issues subjugation. Although tin (Sn)-based vacancyordered DHPs have been widely explored, the intrinsic property conduces low performance output. Titanium (Ti) is a potential substituting candidate of Sn in a vacancy-ordered DHPs structure. It is an environment-friendly element ideal for sustainable perovskite structured compositions. Rudimentary studies of Ti-based vacancy-ordered DHPs emphasized its potential development as an eco-friendly and stable solar cell. In promoting the development of Ti-based vacancy-ordered DHPs as potential absorbers, we summarized herein the recent progress of experimental and theoretical studies of this perovskite material.

Investigation of stability for Cs2TiBr6 perovskite materials exposed to air environment

“…It has been stated that Cs 2 TiBr 6 decomposes in air by forming cesium bromide and titanium dioxide [9]. It has also been reported that a final product of CsX (X = Br and Cl) is obtained based on the loss (evaporation) of highly volatile TiX 4 from Cs 2 TiX 6 in the presence of atmospheric oxygen and moisture [12]. In our study, it is seen that Cs 2 TiBr 6 degrades to CsBr according to our XRD results.…”

“…Oxygen, humidity, light, and temperature are all unfavorable atmospheric conditions that cause the crystal structure of the perovskite material to break down [5]. In the literature, Cs 2 TiBr 6 were obtained by solutionbased, mechanochemical ball milling, evaporation methods (by exposing the CsBr layer to TiBr 4 vapor), and high-temperature melting [5][6][7][8][9][10][11][12]. It has been reported that the surface degradation of Cs 2 TiBr 6 thin films exposed to air occurs within a short time [6].…”

“…Perovskite materials in the ABX 3 (A, B, and X terms are defined above) structure commonly have a cubic or tetragonal crystal structure. Vacancy-ordered double halide perovskites with the general formula A 2 BX 6 are structural derivatives of the ABX 3 perovskite family and are mostly cubic in structure [12]. Cs 2 TiBr 6 perovskites are known as a vacancy-ordered cubic perovskite structure [13].…”

Exploring and optimizing the performance of inorganic Cs2TiBr6 halide perovskite solar cell with Cu2ZnSnS4 as hole transport layer by device simulation

“…As an element with high reserves on the earth, titanium has the advantages of non-toxic, harmless, strong corrosion resistance, and good thermal stability [10]. Experimental results show that inorganic lead-free Ti-based halide perovskite has several ideal combinations of properties, including suitable band gaps, excellent optical absorber, positive defect characteristics, and high stability [11]. In addition, such materials exhibit a combination of tetravalent cations and vacancies, creating a 'vacancy ordered' double perovskite structure with adjustable band gaps.…”

Kinetic study of combined steam and CO2 reforming of methane over Ni-Sr/MgO-ZrO2 catalyst

“…On the contrary, syngas is a combination of hydrogen and carbon monoxide that is used in a variety of petrochemical and metallurgical processes such as the production of methanol or oxo-chemicals. Syngas is used as a varied feedstock in the Fischer-Tropsch process, which is used to produce methanol and hydrocarbons [3]- [5].…”