Sb2S3 Thickness-Related Photocurrent and Optoelectronic Processes in TiO2/Sb2S3/P3HT Planar Hybrid Solar Cells

Abstract

In this work, a comprehensive understanding of the relationship of photon absorption, internal electrical field, transport path, and relative kinetics on Sb2S3 photovoltaic performance has been investigated. The n-i-p planar structure for TiO2/Sb2S3/P3HT heterojunction hybrid solar cells was conducted, and the photon-to-electron processes including illumination depth, internal electric field, drift velocity and kinetic energy of charges, photo-generated electrons and hole concentration-related surface potential in Sb2S3, charge transport time, and interfacial charge recombination lifetime were studied to reveal the key factors that governed the device photocurrent. Dark J–V curves, Kelvin probe force microscope, and intensity-modulated photocurrent/photovoltage dynamics indicate that internal electric field is the main factors that affect the photocurrent when the Sb2S3 thickness is less than the hole diffusion length. However, when the Sb2S3 thickness is larger than the hole diffusion length, the inferior area in Sb2S3 for holes that cannot be diffused to P3HT would become a dominant factor affecting the photocurrent. The inferior area in Sb2S3 layer for hole collection could also affect the Voc of the device. The reduced collection of holes in P3HT, when the Sb2S3 thickness is larger than the hole diffusion length, would increase the difference between the quasi-Fermi levels of electrons and holes for a lower Voc.

Investigation of the effect of S/In molar ratio on physical properties of sprayed In2S3 thin films

“…4 The results reveal high power conversion efficiency of 8.36% than those solid solutions materials over Pt of 7.66%. Wu et al 5 studied hybrid TiO 2 /Sb 2 S 3 / P3HT n-i-p solar cells with Sb 2 S 3 layers of different thickness by CBD method. They reported an optimum efficiency of 1.65% with Sb 2 S 3 thickness of 175 nm.…”

Bismuth oxyhalide based photo-enhanced triboelectric nanogenerators

“…Under illuminated conditions, the limited amount of photogenerated carriers produced in BiOI will contribute to the observed charge exchange. It is understood that while the thicker semiconductor films, owing to their higher absorption coefficient, can absorb more photons and should ideally show enhanced photo-response, however, the effects of enhanced recombination probability and increasing photogenerated carrier diffusion distance to electrode become a major obstacle to this [50]. Therefore, for films grown for longer times, a significant part of the photogenerated charge carriers will recombine i.e., the holes will not diffuse to the surface (discussed later) and therefore not contribute to the charge exchange in TENGs.…”

Rational strategies toward efficient and stable lead-free tin halide perovskite solar cells

“…of a light absorber and its ability to extract photogenerated charge carriers. 54,55 A certain thickness of the perovskite film is needed to ensure the full absorption of light, and ideally, the diffusion length of charge carriers (L D ) should exceed the film thickness to enable efficient collection of the photogenerated charge carriers. The diffusion length can be calculated via the following equation as a function of total recombination rate R:…”