Effect of Na-doped Mo layer as a controllable sodium reservoir and diffusion barrier for flexible Cu(In,Ga)Se2 solar cells
| Autor: | Ju-Hyung Yun, Sung-Tae Kim, Manjeet Kumar, Ho-Jung Jeong, Ye-Chan Kim, Vishwa Bhatt, Jae-Hyung Jang |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Ideality factor
Dominant recombination region Materials science Diffusion barrier 020209 energy Analytical chemistry chemistry.chemical_element 02 engineering and technology Activation energy Series resistance 020401 chemical engineering X-ray photoelectron spectroscopy 0202 electrical engineering electronic engineering information engineering Na incorporation 0204 chemical engineering Flexible CIGS solar cells Doping Copper indium gallium selenide solar cells TK1-9971 General Energy chemistry Molybdenum Electrical engineering. Electronics. Nuclear engineering Short circuit Layer (electronics) Mo:Na layer |
| Zdroj: | Energy Reports, Vol 7, Iss, Pp 2255-2261 (2021) |
| ISSN: | 2352-4847 |
| DOI: | 10.1016/j.egyr.2021.04.040 |
| Popis: | To overcome the absence of sodium (Na) and to prevent undesired impurity diffusion from stainless steel (STS) substrates, a bi-layer molybdenum (Mo) structure consisting of a 1- μ m-thick Mo and Na-doped Mo (Mo:Na) with variable thickness was utilized as the back contact layer in copper–indium–gallium–selenide (CIGS) solar cells. Na ions were supplied to the CIGS absorber layer from the Mo:Na layer, and the amount of Na ions was controlled by changing the thickness of Mo:Na layer. The Na doping to the CIGS layer is verified by the X-ray photoelectron spectroscopy (XPS) and the dynamic secondary ion mass spectroscopy (D-SIMS). The recombination process in the bulk CIGS and the CdS/CIGS junction has been analyzed by temperature dependent current density–voltage (J–V–T) measurement. The D-SIMS showed that the amount of Na ions in the CIGS layer grown on Mo/Mo:Na/STS is comparable with that in the conventional CIGS film deposited on Mo coated soda-lime glass. Moreover, the bi-layer Mo also acts as a diffusion barrier layer against the Fe atoms, which deteriorate the quality of CIGS. The higher content of Na ions and the lower content of Fe ions in the CIGS layer lowered the recombination activation energy, series resistance and ideality factor, leading to improved junction quality. As a result, the short circuit current density and power conversion efficiency of the CIGS on the Mo and 600-nm-thick Mo:Na were improved by 8.1 and 69.4%, respectively, compared with those of CIGS solar cells fabricated without a Mo:Na layer. |
| Databáze: | OpenAIRE |
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