Comparison of Sulfur Incorporation into CuInSe₂ and CuGaSe₂ Thin‐Film Solar Absorbers

Abstract

Figure 12. The corresponding a,c) EQE and b,d) J-V graphs of the CGSe sample with [Cu]/[III] ¼ 0.86 and 1.14, before and after sulfurization. The EQE of CGSe-Ref is not included in c), because it is zero for all wavelengths.

Postdeposition Sulfurization of CuInSe2 Solar Absorbers by Employing Sacrificial CuInS2 Precursor Layers

“…The lower J SC after sulfurization has been attributed to: 1) emergence of an electron barrier at the CuInS 2 /CuIn(S,Se) 2 interface, 2) shrinkage of the space‐charge region width due to higher doping in the newly formed CuInS 2 , or 3) enhanced recombination at the grain boundaries (GBs) owing to the higher S concentration therein. In our recent study of Cu‐poor CuInSe 2 (CISe), [ 15 ] we confirmed that a 180 nm‐thick conformal surface CIS layer is formed after absorber sulfurization at 530 °C, decreasing both FF and J SC . At the same time, we found that these adverse effects can be alleviated by lowering the treatment temperature to 430 °C, at which an inhomogeneous surface CuIn(S,Se) 2 (CISSe) alloy is produced instead.…”

“…Further details on the CdS deposition procedure can be found elsewhere. [ 13,15 ] To finish the cells, a window layer stack of intrinsic ZnO and aluminum‐doped ZnO (i‐ZnO + ZnO:Al) with the total thickness of 270 nm and sheet resistance of 45 Ω sq −1 was deposited on all pieces by RF magnetron sputtering. Finally, 15 individual cells with an area of 0.05 cm 2 were defined for each sample by mechanical scribing.…”

“…More details about the sample preparation with FIB can be found in our earlier studies. [ 5,13–15 ] In addition, compositional depth profiles were obtained with glow discharge optical emission spectroscopy (GDOES) using a Spectruma Analytik GMBH GDA 750 instrument with the sputtering crater of 4 mm in diameter.…”

“…[ 9 ] For the purpose of avoiding toxic H 2 S, several studies performed sulfurization of coevaporated absorbers in elemental sulfur atmosphere with the intention of similar device improvement. [ 5,10–15 ] However, this approach led to the formation of a pure CuInS 2 (CIS) layer on top of Cu‐depleted CIGSe with a Ga pile‐up near the CIGSSe/CIS interface. This approach resulted in a reduced fill factor (FF) and blocking behavior, presumable caused by the wide‐gap Ga‐rich CIGSe near the interface.…”

Influence of chemical composition and doping on optical properties of thallium selenide layers prepared by adsorption/diffusion method

“…For example, solar cells based on CuGaSe 2 , CuInSe 2 and CuInS 2 widely used in solar energy harvesting have an efficiency of 18.8% [16]. Therefore, many studies have focused on methods for the preparation of these ternary selenide thin films, such as spray pirolysis [17], direct current-magnetron sputtering [18], thermal co-evaporation [19], low temperature pulsed electron deposition [20], electrodeposition [12], solvothermal [21] and others. However, most of these methods typically consist of many stages, require sophisticated equipment and special conditions such as high temperature, vacuum, and conductive substrates, making them unsuitable and expensive for manufacturing most polymers.…”