DLTS investigations on CIGS solar cells from an inline co-evaporation system with RbF post-deposition treatment

Abstract

In this study, Deep Level Transient Spectroscopy (DLTS) measurements have been performed on Cu(In,Ga)Se2 (CIGS) solar cells from an inline co-evaporation system. The focus of this investigation is directed on the effect of rubidium-fluoride (RbF)-post-deposition treatment (PDT) on the defects in the CIGS absorber layer. Different traps can be identified and their properties are calculated. Herein, different methods of evaluations have been used to verify the results. Specifically, one minority trap around 400 meV was found to show a significant reduction of the trap density due to the alkali treatment. In contrast, a majority trap at approximately 600 meV is unaffected.

Stability of Cu(InxGa1−x)Se2 Solar Cells Utilizing RbF Postdeposition Treatment under a Sulfur Atmosphere

“…[ 8 ] Helder et al employed deep‐level transient spectroscopy (DLTS) to observe that RbF PDT reduced the concentration of an E V + 0.4 eV trap by a factor of 3−4 x . [ 21 ] After aging, the J 0 versus T curves converged and there was less separation between the two devices. Defect studies are needed to determine whether increased J 0 after aging is related to an increase in defect concentration, available in Mendeley Data at https://doi.org/10.17632/ghc3p5zxh8.1, reference number 22.…”

How small changes make a difference: Influence of low silver contents on the effect of RbF‐PDT in CIGS solar cells

“…One further reason for the strong decrease of the could be the presence of deep defects, causing an increased Shockley–Read–Hall (SRH) recombination and therefore decreased carrier lifetime. The effect of RbF‐PDT on deep defects in CIGS (without silver) has been investigated by deep level transient spectroscopy (DLTS) and other capacitive measurement techniques already in the last years, reporting a passivating effect of Rb which results in an enhanced carrier lifetime 12,21,28 . Therefore, it is reasonable to investigate the effect in ACIGS absorber materials.…”

“…For higher source temperatures above 520 C, the Rb and Na concentration increases in that region carrier lifetime. 12,21,28 Therefore, it is reasonable to investigate the effect in ACIGS absorber materials. The results of reverse DLTS (RDLTS) measurements are shown in Figure 7A.…”

“…The evaluation of the measured temperature scans have been performed by a maximums analysis of the peaks, where the position is tracked resulting in a data set in the Arrhenius plot for each trap, with the emission time constant τ or the emission rate e T plotted over the inverse temperature 1000=T. The measurement technique is also described elsewhere 28. 4.2.2 | CV measurementsCV measurements have been performed with the cryogenic setup and PhysTech Hera DLTS system in dark, at room temperature, and 200K in order to test the sensitivity of the measurements to temperature changes.…”

A comprehensive insight into deep-level defect engineering in antimony chalcogenide solar cells

“…This technique has been widely explored for the characterization of defects in mature PV technologies ( e.g. , Si, 56 GaAs, 57,58 CIGS, 59 and CdTe 60,61 ), and emerging perovskite solar cells. 62–64…”