Band-Gap Tuning of Organic–Inorganic Hybrid Palladium Perovskite Materials for a Near-Infrared Optoelectronics Response

Abstract

Organic–inorganic hybrid material is a recent hot topic in the scientific community. The best band gap for the entire solar absorption spectrum is about 1.1 eV. However, the lead perovskite band gap is about 1.5 eV. Therefore, developing organic–inorganic hybrid material toward the broader light harvesting of the solar spectrum is extremely urgent. In this study, we prepare three kinds of organic–inorganic hybrid palladium perovskite materials, including (CH 3 NH 3 ) 2 PdCl 4 , (CH 3 NH 3 ) 2 PdCl 4– x Br x , and CH 3 NH 3 PdI 3 , for an optoelectronic response. The absorption cut offs of (CH 3 NH 3 ) 2 PdCl 4 , (CH 3 NH 3 ) 2 PdCl 4– x Br x , and CH 3 NH 3 PdI 3 are approximately 600, 700, and 1000 nm, respectively. The band gaps of (CH 3 NH 3 ) 2 PdCl 4 , (CH 3 NH 3 ) 2 PdCl 4– x Br x , and CH 3 NH 3 PdI 3 are determined to be approximately 2.15, 1.87, and 1.25 eV, respectively. To the best of our knowledge, this is the first study that discusses adsorption properties and photoelectric behavior of organic–inorganic hybrid palladium perovskite materials. Interestingly, the photoelectric response of the devices based on CH 3 NH 3 PdI 3 reaches 950 nm. The results will attract attention in the fields of optical recorders, optical memory, security, light capture, and light treatment.

Organic‐Inorganic Hybrid Perovskite Single Crystals: Crystallization, Molecular Structures, and Bandgap Engineering

“…[88] Even though the band structure is mainly contributed by Pb and halogen atoms, organic cations can also tune the band structure, electronic and optical properties of organic-inorganic halide perovskites by influencing the PbÀ X lengths or XÀ PbÀ X angles. [94][95][96][97] Snaith et al synthesized perovskites based on methylammonium lead triiodide, in which methylammonium (CH 3 NH 3 + ) (MA) was replaced by formamidinium (HC(NH 2 ) 2 + ) (FA). At room temperature, FAPbI 3 is found in a cubic structure, [98] which is easily transforming into a yellow polymorph with hexagonal symmetry (P63mc) unsuitable for PV-applications.…”

“…The orientation of the MA cations plays an important role in structural stability, the electronic properties of surfaces and phase transition . Even though the band structure is mainly contributed by Pb and halogen atoms, organic cations can also tune the band structure, electronic and optical properties of organic‐inorganic halide perovskites by influencing the Pb−X lengths or X−Pb−X angles . Snaith et al.…”

Synthesis, Crystal Structure and Photoelectric Response of All‐Inorganic Copper Halide Salts CsCuCl3

“…Thus, it is necessary to develop a high‐performance, low‐cost, corrosion‐resistant all‐inorganic and lead‐free metal halide salts (MHS) , . Numerous researchers developed alternative lead‐free MHS materials in the recent years . However, the studies about the photoelectric response of copper halide salts are few at present , .…”

A Review on Lead-Free Hybrid Halide Perovskites as Light Absorbers for Photovoltaic Applications Based on Their Structural, Optical, and Morphological Properties

“…Interestingly, the photoelectric response of CH 3 NH 3 PdI 3 reached 950 nm. The results have drawn attention in the fields of optoelectronics and photovoltaics [129].…”