Miscellaneous and Perspicacious: Hybrid Halide Perovskite Materials Based Photodetectors and Sensors

Abstract

abbreviated as AMX 3 (A is an organic cation, e.g., CH 3 NH 3 + , HN=CHNH 3 + ; M is a metal cation, e.g., Sn 2+ , Pb 2+ ; X is a halide anion, e.g., Cl − , Br − , I −). In their crystal framework, corner-sharing BX 6 octahedrons form the 3D network with the A cations situated in the cuboctahedral interstices. [4,5] The inorganic components of the halide perovskite provide the conductive backbones required by the carrier's ordered transmission and also provide the thermal and mechanical stability of the material. The organic components, on the other hand, function as templates via hydrogen bonds during the perovskite film formation process. Different from 3D perovskites, layer-structured 2D perovskite materials follow the (RNH 3) 2 (A 3) n-1 M n X 3n+1 structure, where R is an alkyl or aromatic moiety larger than A, and n is the number of inorganic layers between the organic chains. [6,7] When n→∞, the structure converts to 3D perovskite. When n is a limited integer, quantum well structures form with layers of AX 4 2− separated and supported by a layer of organic cations via weak van der Waals forces. The inorganic components provide high carrier mobility and wide bandgap tunability. The organic components, being either large aliphatic or aromatic ammonium cations, can enhance hydrophobicity by preventing water molecules from penetrating and destroying the inorganic layers. Thus 2D perovskites usually demonstrate improved environmental stability against moisture. [8-10] Importantly, 2D perovskite crystals also showed unique optical properties such as deep blue emission and strong excitonic effect due to the strong quantum well effect. [11] Furthermore, targeting on the instability issue of hybrid perovskites under high-temperature and humid environments, scientists prompted all-inorganic perovskites (e.g., CsPbX 3) by replacing the organic component with inorganic ions. [12] Besides the rapid development of perovskite-based photovoltaics, [13-16] other perovskite-related devices including lightemitting diodes (LED), [17-20] laser, [21-23] transistors, [24] thermoelectric generators, [25] photodetectors for UV-NIR photons, [26-29] and various sensors for gas, chemical, and pressure have been widely studied. [30-33] Among all these potential applications, detectors and sensors became very active areas of research and even the third-largest application behind photovoltaics and LEDs (Figure 1). This trend could, again, be attributed to the favorable intrinsic properties of hybrid halide perovskites such as direct and tunable bandgaps with significant absorption coefficients, ultralong charge carrier lifetimes/diffusion lengths, high carrier mobilities, low charge carrier recombination, broad Optoelectronic devices based on perovskite materials have shown significant improvement due to the direct and tunable bandgaps, large absorption coefficients, broad absorption spectra, high carrier mobilities, and long carrier diffusion lengths. In addition to the excellent performance in solar cells, scientists have utilized per...

Material exploration via designing spatial arrangement of octahedral units: a case study of lead halide perovskites

“…Halide perovskites, with the common formula ABX 3where A is an organic or alkali cation, B is commonly Pb 2+ , and X is a halogen anionhave attracted tremendous attention as semiconducting materials not only for thin-film solar cells [1,2] but also for photodetectors [3][4][5] and light-emitting diodes (LEDs) [6][7][8][9] due to their superior optoelectronic properties [10][11][12] such as suitable direct allowed bandgaps [13], small effective masses for both holes and electrons [14], high optical absorption coefficients [15], long photogenerated carrier diffusion lengths and lifetimes [16], and high defect tolerance [17][18][19][20] as well as solution processability that enables low production costs. Structurally, these perovskites consist of a three-dimensional (3D) corner-sharing network of [BX 6 ] octahedra (i.e., BX 3 ), with the "A" cations occupying 12-fold cuboctahedral voids within the network and counterbalancing the charge of [BX 3 ]extended anion.…”

Performance improvement of UV photodetectors using Cd-doped ZnO nanostructures

“…Photodetectors can be appraised using parameters such as detectivity (D*) and responsivity (R), which are obtained using equations ( 3)-( 4) [37].…”

The Impact of PbI2:KI Alloys on the Performance of Sequentially Deposited Perovskite Solar Cells

“…Owing to the exceptional optoelectronic properties, such as tunable bandgaps, long carrier lifetimes, high optical absorption coefficients, and high defect tolerance, [1][2][3] lead halide perovskites find applications in solar cells, [4][5][6][7] light-emitting diodes, [8][9][10][11] lasers, [12][13][14] photodetectors, [15][16][17][18][19] and many other optoelectronic devices. [20,21] As a star material for third-generation solar cells, perovskite-based solar cells (PSCs) have achieved significant improvements, with the power conversion efficiency (PCE) increased from 3.8 % in 2009 to 25.5 % in 2020.…”