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

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.