Photo-Induced Black Phase Stabilization of CsPbI3 QDs Films

Abstract

α-CsPbI3 quantum dots (QDs) show outstanding photoelectrical properties that had been harnessed in the fabrication of perovskite QDs solar cells. Nevertheless, the stabilization of the CsPbI3 perovskite cubic phase remains a challenge due to its own thermodynamic and the presence of surface defects. Herein, we report the optimization of the CsPbI3 QDs solar cells, by monitoring the structure, the morphology and the optoelectronic properties after a precise treatment, consisting of the conventional solvent washing with a time limited ultraviolet (UV) exposure combination, during the layer-by-layer deposition. The UV treatment compensates the defects coming from the essential but deleterious washing treatment. The material is stable for 200 h and the PCE improved by the 25% compared with that of the device without UV treatment. The photo-enhanced ion mobility mechanism is discussed as the main process for the CsPbI3 QDs and solar cell stability.

Interfacial modification of perovskite solar cells via Cs2CO3: Computational and experimental approach

“…The intensity of the peak at 12.7 o is decreased with Cs2CO3 treatment, this peak is characteristic of residual PbI2 as well as a slight decrease of the peak at 11.5 o which corresponds to the δ-phase of FAPbI3 (Cho et al, 2017). The photoactive black phase of the perovskite layer is likely to be present by the addition of Cs (Erazo et al, 2020;Saliba et al, 2016b;Yavari et al, 2021). The absorption spectra are similar in both cases as illustrated in (Fig.…”

Polar solvent-free room temperature synthesis of CsPbX3 (X = Br, Cl) perovskite nanocubes

“…The observed bands at 3392 and 3153 cm −1 correspond to N–H stretching modes of guanidinium or oleylammonium molecules. 56–59 The absorption peak observed at around 1668 cm −1 demonstrates ν CN of guanidinium groups. 56,59 Also, the observed signals at around 1533 and 1405 cm −1 indicate asymmetric and symmetric stretching modes of the COO− group of oleate species, respectively.…”

“…56,59 Also, the observed signals at around 1533 and 1405 cm À1 indicate asymmetric and symmetric stretching modes of the COOÀ group of oleate species, respectively. 57,58 The absorption peaks between 2780-3000 cm À1 show stretching of the C-H bonds in the long alkyl chains of the oleate or oleylammonium molecules. In a recent work, the spontaneous replacement of the oleylammonium with GA at the surface of the CsPbI 3 nanocrystals was demonstrated in the hot injection method.…”

Effect of reaction temperature on CsPbBr3 perovskite quantum dots with photovoltaic applications

“…Meanwhile, the FF shows short circuit issues, probably caused by contact faults [2,3,14]. However, the main reason is the silver paint and the influence of the TiO2 films on the charge transport from the PQDs [2,51]. Therefore, improving the deposition of TiO2, CsPbBr3 PQDs is essential.…”

“…devices were made with the following structure: FTO/c-TiO2/m-TiO2/PQDs/spiro-OMeTAD/Ag[3,10,28,51]. Then, these solar cells were characterized, and JV curves were plotted.…”