Synthesis and Investigation of the Properties of Organic-Inorganic Perovskite Films with Non-Contact Methods

Abstract

We present the results of studies of the photoelectric properties of perovskite CH3NH3PbI2.98Cl0.02 films deposited on a glass substrate using the spin-coating method. The unit cell parameters of perovskite are determined, by using X-ray diff ractometry. It is shown that the fi lm morphology represents a net of non-oriented needle-like structures with significant roughness and porosity. In order to investigate the properties of the films obtained, we used non-contact methods such as transmission and reflection measurements and the measurements of the spectral characteristics of the small-signal surface photovoltage. The non-contact method of spectral characteristics of the small-signal surface photovoltage and the transmission method reveal information about the external quantum yield in the films studied and about the diffusion length of minority carriers in the perovskite films. As a result of this analysis, it has been established that the films are naturally textured, and their bandgap is 1.59 eV. It is shown that, in order to correctly determine the absorption coefficient and the bandgap values, the Urbach effect should be accounted for. The diffusion length of minority carriers is longer than the fi lm thickness, which is equal to 400 nm. The films obtained are promising materials for solar cells and optoelectronic devices.

Investigation and application of hot carrier phenomenon in photovoltaics

“…The light from a halogen lamp was directed through a monochromator and beam splitter onto the sample under investigation. A non-destructive method was employed using a press-on ITO electrode with an approximate area of 7  7 mm² (Kostylyov et al, 2021). A silicon etalon photodiode is used as a reference photosensor.…”

“…Šviesa iš halogeninės lempos per monochromatorių ir spindulio skirstytuvą nukreipiama į tiriamąjį bandinį. Taikyta neardomoji metodika, kai naudojamas prispaudžiamas 7 × 7 mm² ploto ITO elektrodas (Kostylyov et al, 2021).…”

“…Fig.2.9. Schematic experimental setup for detection capacitive photovoltage signal of Si diodes containing surface PSi layer(Kostylyov et al, 2021) …”