Modulating the optical and electrical properties of MAPbBr3 single crystals via voltage regulation engineering and application in memristors

Abstract

Defect density is one of the most significant characteristics of perovskite single crystals (PSCs) that determines their optical and electrical properties, but few strategies are available to tune this property. Here, we demonstrate that voltage regulation is an efficient method to tune defect density, as well as the optical and electrical properties of PSCs. A three-step carrier transport model of MAPbBr3 PSCs is proposed to explore the defect regulation mechanism and carrier transport dynamics via an applied bias. Dynamic and steady-state photoluminescence measurements subsequently show that the surface defect density, average carrier lifetime, and photoluminescence intensity can be efficiently tuned by the applied bias. In particular, when the regulation voltage is 20 V (electrical poling intensity is 0.167 V μm−1), the surface defect density of MAPbBr3 PSCs is reduced by 24.27%, the carrier lifetime is prolonged by 32.04%, and the PL intensity is increased by 112.96%. Furthermore, a voltage-regulated MAPbBr3 PSC memristor device shows an adjustable multiresistance, weak ion migration effect and greatly enhanced device stability. Voltage regulation is a promising engineering technique for developing advanced perovskite optoelectronic devices.

Interface Dipole Induced Field‐Effect Passivation for Achieving 21.7% Efficiency and Stable Perovskite Solar Cells

“…Recently, for the popular investigated organic-inorganic halide perovskite materials CH 3 NH 3 PbI 3 (MAPbI 3 ), a direct optical study unraveled that the strong recombination at surface dominates the carrier lifetime losses and thus the performance criteria of the PSCs. [12,13] In addition, together with ion migration in the perovskite film, the interfacial recombination is recognized as a main factor for lots of the observed hysteresis behaviors, which increases the uncertainty of device performance. [14] Therefore, effective interfacial passivation strategies at the contacts interface to suppress the recombination becomes increasingly critical to achieving higher performance PSCs.…”

Simultaneous Optimization of Charge Transport Properties in a Triple-Cation Perovskite Layer and Triple-Cation Perovskite/Spiro-OMeTAD Interface by Dual Passivation

“…Also, the diffusion of free carriers into the bulk region is induced, resulting in more fluorescence emission through the free carrier, thereby facilitating carrier transport and prolonging the free-carrier lifetime (τ 3 ). 63 It was found that the triple-cation perovskite films washed with 2I-Ac, 2Br-Ac, and 2Cl-Ac molecules exhibited a longer τ 3 than that of the control sample as shown in Figure 2 d. The significantly extended lifetime of the triple-cation perovskite films with these three molecules represents the successful suppression of defects by the severe carrier nonradiative recombination in the triple-cation perovskite bulk. As shown in Figure 2 d, the TRPL measurement shows that the τ 3 lifetime is increased from 30.29 to 110.60, 57.87, and 34.78 ns in washing with 2I-Ac, 2Br-Ac, and 2Cl-Ac molecules, respectively.…”

Low-temperature solution-processed SnO2 electron transport layer modified by oxygen plasma for planar perovskite solar cells

“…Fast decay components correspond to an effective charge extraction from perovskite to the ETL layer, whereas s 2 and s 3 represent the radiative recombination of free carriers. 37,38 In addition, the LTP-SnO 2 sample exhibits a low PL decay time (s 1 ¼ 2.28, s 2 ¼ 7.24) compared to LT-SnO 2 (s 1 ¼ 2.48, s 2 ¼ 11.5), indicating an effective electron transfer from the perovskite to ETL. The average recombination lifetime (s avg ) is calculated using the equation below:…”

“…† The value of s 1 , s 2 , and s 3 correspond to the decay time of fast, intermediate, and slow component respectively. Fast decay components correspond to an effective charge extraction from perovskite to the ETL layer, whereas s 2 and s 3 represent the radiative recombination of free carriers 37,38. In addition, the LTP-SnO 2 sample exhibits a low PL decay time (s 1 ¼ 2.28, s 2 ¼ 7.24) compared to LT-SnO 2 (s 1 ¼ 2.48, s 2 ¼ 11.5), indicating an effective electron transfer from the perovskite to ETL.…”