Large Band Gap Narrowing and Prolonged Carrier Lifetime of (C₄H₉NH₃)₂PbI₄ under High Pressure

Abstract

Due to their superior optical and electronic properties and good stability, 2D organic–inorganic halide perovskites (OIHPs) exhibit strong potential for optoelectronic applications. However, the large band gap, short carrier lifetime, and high resistance hinder their practical performance. In this work, the band gap is successfully tuned, the carrier lifetime is prolonged, and the resistance of (C 4 H 9 NH 3 ) 2 PbI 4 (BA 2 PbI 4 ) is reduced directly using high pressure. The band gap is decreased to less than 1 eV at 35.0 GPa, and the highest pressure is studied. The carrier lifetime at 9.9 GPa is 20 times longer than that at ambient conditions. Moreover, the resistance is reduced by four orders of magnitude at 34.0 GPa accompanying band gap narrowing. This work indicates that pressure plays an effective role in tuning the optical and electronic structures of BA 2 PbI 4 , and also provides a strategy to synthesize high‐performance OIHP materials.

Harvesting High-Quality White-Light Emitting and Remarkable Emission Enhancement in One-Dimensional Halide Perovskites Upon Compression

“…More intriguing is that the C 4 N 2 H 14 PbCl 4 crystal exhibited the periodical pressure-induced emission (PIE) phenomenon until 35.1 GPa, which has never been reported in previous PIE systems. This phenomenon not only breaks the traditional thinking that the pressure-induced PL quenching 31 and the PIE effect only exist in the low-pressure region, 29 but also corrects the misconception that the decrease of crystallinity of perovskite materials will lead to the destruction of optical properties, 36 thus further enriching the concept and scope of the PIE phenomenon. Moreover, the excellent properties of materials under ultrahigh pressure are required in aerospace application field and geological engineering.…”

“… 18 − 24 Recently, scientists began to shift the focus from high-pressure 3D perovskites research to LDHPs. 25 − 29 Notably, the pressure-induced phase transition and band gap structure tuning on LDHPs render the pressure a feasible strategy to optimize its properties. 30 − 32 For example, the series of LDHPs [C n H 2 n +1 NH 3 ] 2 PbI 4 ( n = 4, 8, 12) were confirmed to have longer alkylamine cations that lead to less ease of phase transition upon compression; 33 (PEA)PbI 4 was observed to have a direct–indirect band gap transition at around 5.8 GPa, 34 and BA 2 PbBr 4 was found to have a pressure-induced photoluminescence enhancement below 1.0 GPa.…”

Temperature‐Gradient‐Controlled Method Enabling Shape Control of 2D Perovskite Single Crystals for Photodetection

“…This is consistent with previous reports. [ 23,31 ] Figure 3d shows the photoluminescence (PL) spectra of BA 2 PbI 4 and BA 2 FAPb 2 I 7 crystals under 420 nm light excitation. Strong excitation peaks were observed at 520 and 577 nm in the PL spectra.…”

Performance optimization strategies of halide perovskite-based mechanical energy harvesters

“…61 Additionally, the release of lead halide compounds from the halide perovskites would easily reside and accumulate on human organs, such as the kidney, liver and nervous system, resulting in the destruction of heme activity in the blood and signal transduction throughout the central nervous system. 62,63 Furthermore, heavy metal lead is also a huge concern for the environmental pollution, ranging from air and water pollution to agricultural soils and food chain pollution. 64 Therefore, reducing the toxicity of halide perovskites by doping non-toxic elements or using lead-free perovskites is crucial for the future development of biocompatible and eco-friendly HP-PENG.…”