Nucleation Regulation and Anchoring of Halide Ions in All‐Inorganic Perovskite Solar Cells Assisted by CuInSe₂ Quantum Dots

Abstract

Ionic feature of halide perovskites may lead to the formation of defect states in the polycrystalline films, which can deteriorate the device performance. To solve this issue, a low‐temperature seed‐assisted growth method can contribute to defect‐passivated CsPbI1.2Br1.8 perovskite films by introducing CuInSe2 quantum dots (QDs). As a result, the migration channels inside perovskite grains can be obviously suppressed, but few positive effects on the ions migration in grain boundaries. Conversely, this appearance demonstrate that the location of CuInSe2 QDs is grain interior, but not grain boundary. Meanwhile, the lower defect density can help promoting device efficiency from 8.97% to 10.26%, which is among the high‐efficiency level. Besides, this work can also provide an in‐depth insight into the issue of photoinduced halide segregation.

[BMP]+[BF4]−-Modified CsPbI1.2Br1.8 Solar Cells with Improved Efficiency and Suppressed Photoinduced Phase Segregation

“…The absorption spectra in Figure 2b indicate that the control film and the [BMP] + [BF 4 ] −modified CsPbI 1.2 Br 1.8 films process a similar sharp-cutting absorption edge at ~605 nm corresponding to a bandgap of ~2.05 eV, which is consistent with the values reported in the literature [39,41]. However, this increase in mass concentration leads to a slight decrease in the absorption intensity in the 500-580 nm absorption region, mainly due to the addition of [BMP] + [BF 4 ] − in the perovskite films.…”

“…Furthermore, the peak intensity of the perovskite film decreases as the mass concentration of the [BMP] + [BF 4 ] − increases to 3 mg mL −1 . This suggests that higher mass concentrations may weaken the crystallinity of the modified films with increased scattering from grain boundaries or intragranular defects, which is not beneficial for the photovoltaic performance of the final devices[40].The absorption spectra in Figure2bindicate that the control film and the [BMP] + [BF 4 ] −modified CsPbI 1.2 Br 1.8 films process a similar sharp-cutting absorption edge at ~605 nm corresponding to a bandgap of ~2.05 eV, which is consistent with the values reported in the literature[39,41]. However, this increase in mass concentration leads to a slight decrease in the absorption intensity in the 500-580 nm absorption region, mainly due to the addition of [BMP] + [BF 4 ] − in the perovskite films.…”

Construction Au/FAPbI3 Schottky Heterojunction towards a High-Speed Electron Transfer Channel for High-Performance Perovskite Quantum Dot Solar Cells

“…As depicted in Figure a, the SCLC curve can be segmented into three distinct regions: the ohmic region, defect filling region, and child region. Experimental data reveals that the carrier mobility is lower in the FAPbI 3 -based device (0.74 × 10 –3 cm 2 V –1 s –1 ) compared to that of the Au/FAPbI 3 -based device (1.46 × 10 –3 cm 2 V –1 s –1 ), indicating that the constructed HETC could accelerate electron migration . Furthermore, transient photovoltage (TPV) measurements demonstrate that the Au/FAPbI 3 -based device exhibits a longer decay time (from 8.49 ms to 16.40 ms ) compared to the FAPbI 3 -based device.…”

Modulation of Photoinduced Phase Segregation and Stress-Driven Nanoscale Cracking in Hybrid Halide Perovskite Solar Cells

“…Several mechanisms have been proposed to explain PIHS in hybrid halide perovskites. ,,− Among them, defect induced ion segregation has attracted the attention of numerous researchers. Barker et al suggested that the gradient of carrier generation rate generated inside the film drives the separation of halide phases, thus resulting in an iodide-rich low band gap region close to the illuminated surface of the film .…”