A Review on Additives for Halide Perovskite Solar Cells

Figure 3. The impact of MABr treatment on the scanning electron microscopy (SEM) images of film morphology (MAPbI 3 films a) without and b) with MABr treatment), c) ultraviolet-visible (UV-vis) absorption spectra, and d) XRD patterns of the perovskite films. Reproduced with permission. [61] Copyright 2016, Springer Nature. e) Schematic illustration and f) SEM images of the molecule-passivated RP/3D heterostructure. Reproduced with permission. [115] Copyright 2018, Royal Society of Chemistry. g) Schematic representation of the 1D/3D heterostructure evidenced by solid-state NMR proximity measurements. Reproduced with permission. [40] Copyright 2019, Springer Nature. h) Secondary-ion mass spectrometry (SIMS) measurement of interdiffusion-grown MAPbI 3 films on indium tin oxide (ITO) glass. Reproduced with permission.

Section: Introductionmentioning

confidence: 99%

Toward Efficient and Stable Perovskite Solar Cells: Choosing Appropriate Passivator to Specific Defects

Zhou

et al. 2020

“…[ 1–3 ] In fact, their power conversion efficiency (PCE) has been increased from 3.8% to 25.2% in just a few years. [ 4–6 ] Unfortunately, the organic components in the perovskite composition make them susceptible to stressing conditions including high temperature, chemical, and ultraviolet radiation. [ 7–10 ] Inorganic cesium halide perovskites (CsPbX 3 , X = I or Br) without the organic component are attractive in the long run because of their advantages in thermal stability, and chemical resistance.…”

Section: Introductionmentioning

confidence: 99%

Low‐Temperature Crystallization of CsPbIBr₂ Perovskite for High Performance Solar Cells

Zhang

Wang

et al. 2020

Organic-inorganic metal halide perovskites are superstars for photovoltaics and optoelectronics due to their excellent defect tolerance, high charge mobility, tunable optical bandgap, and high absorption coefficient. [1-3] In fact, their power conversion efficiency (PCE) has been increased from 3.8% to 25.2% in just a few years. [4-6] Unfortunately, the organic components in the perovskite composition make them susceptible to stressing conditions including high temperature, chemical, and ultraviolet radiation. [7-10] Inorganic cesium halide perovskites (CsPbX 3 , X ¼ I or Br) without the organic component are attractive in the long run because of their advantages in thermal stability, and chemical resistance. [11-13] CsPbI 3 possesses an attractive bandgap of %1.73 eV to absorb most of the solar energy in visible spectrum; PSCs based on CsPbI 3 have achieved champion efficiencies as high as 19.03%. [14] Unfortunately, the desired PV active α-phase CsPbI 3 is not thermodynamically stable at room temperature. It can be easily transitioned to PV-inactive yellowish δ-phase. Such conversion leads to a considerable drop in PCE and stability. [15,16] Extensive efforts have been devoted to address these issues. Bromine has been used to partially or even completely substitute iodine in the CsPbX 3 composition. For example, a PCE of over 16% has been achieved for CsPbI 2 Br PSCs with relatively enhanced stability. [17,18] Furthermore, a PCE of 10.79% has been attained for CsPbBr 3-based PSCs with an extraordinarily high open-circuit voltage exceeding 1.6 V and decent stability upon Sm 3þ ion doping. [19] Nevertheless, its wide bandgap of %2.3 eV leads to reduced capability of solar light harvesting, which in turn limits its application. [20]

“…In the past few years, for achieving this target, quite a few strategies have been proposed, [ 28–37 ] among which, additive engineering has significantly encouraged the improvement of power conversion efficiency (PCE) performance and stability. [ 38,39 ] The reported additives not only gift perovskite films with enhanced crystallinity along with enlarged grain size, but also are advantageous to passivate defect states, thereby lessening the detrimental carrier recombination. Moreover, it is worthwhile mentioning that many additives play a crucial role in the stability improvement.…”

Section: Introductionmentioning

confidence: 99%

Efficient Bidentate Molecules Passivation Strategy for High‐Performance and Stable Inorganic CsPbI₂Br Perovskite Solar Cells

Yin

2020

Cesium-based all-inorganic perovskites have witnessed extraordinary advances owing to their eye-catching thermal-resistance and photoelectric properties in optoelectronics and photonics application, including solar cells, [1-5] light-emitting diodes, [6,7] photodetectors, [8,9] nanolasers application, [9,10] and so on. In particular, inducing a prominent trade-off between the light absorption and phase stability in comparison with CsPbBr 3 and CsPbI 3 perovskites, [11-13] the mixed-halide inorganic CsPbI 2 Br perovskites with the suitable bandgap have great potential in the application of burgeoning tandem solar cells and semitransparent photovoltaic devices. [14-16] Unfortunately, the serious energy losses (E loss) derived from deleterious nonradiative recombination [17,18] and inimical phase transformation to photo-non-active phase upon exposing to high humidity environment [15,19] are still the primary bottleneck hindering the further commercialization. Consequently, fabricating efficient and stable CsPbI 2 Br perovskite solar cells (PSCs) is a challenging but crucial and meaningful task. It is widely reported that the proliferated dangling bonds at the grain boundaries cause the formation of undesired point defects that result in the carrier recombination and propel the phase transformation to nonfunctional δ phase. [20-22] Moreover, the inimical pinholes caused by poor crystallization make grain boundaries the most susceptible to external erosion, such as moisture and oxygen. [23-25] Thus, considering that the detrimental nonradiative recombination and moisture-driven phase transformation preferentially occur along the weakest grain boundaries region, modulating perovskite crystallization to lower grain boundaries density and passivating defects at the grain boundaries are desirable for fabricating high-quality and stable perovskite films. [26,27] In the past few years, for achieving this target, quite a few strategies have been proposed, [28-37] among which, additive engineering has significantly encouraged the improvement of power conversion efficiency (PCE) performance and stability. [38,39] The reported additives not only gift perovskite films with enhanced crystallinity along with enlarged grain size, but also are advantageous to passivate defect states, thereby lessening the detrimental carrier recombination. Moreover, it is worthwhile mentioning that many additives play a crucial role in the stability improvement. Ma et al. found that guanidinium cations (GA þ) additives in the substitutional sites of perovskite lattice could stabilize the α phase and facilitate a high crystalline CsPbI 2 Br through the relaxation of the lattice strain and the formation of hydrogen bonds, which renders a low fabrication temperature of 140 C. Moreover, GA þ-mediated devices exhibited the superior moisture stability and decreased by only 6% of origin PCE value after 1000 h aging. [31] Wang et al. judiciously incorporated CuBr 2