Atomic Layer Deposition of Ultrathin ZnO Films for Hybrid Window Layers for Cu(Inx,Ga1−x)Se2 Solar Cells

Abstract

The efficiency of thin-film chalcogenide solar cells is dependent on their window layer thickness. However, the application of an ultrathin window layer is difficult because of the limited capability of the deposition process. This paper reports the use of atomic layer deposition (ALD) processes for fabrication of thin window layers for Cu(Inx,Ga1−x)Se2 (CIGS) thin-film solar cells, replacing conventional sputtering techniques. We fabricated a viable ultrathin 12 nm window layer on a CdS buffer layer from the uniform conformal coating provided by ALD. CIGS solar cells with an ALD ZnO window layer exhibited superior photovoltaic performances to those of cells with a sputtered intrinsic ZnO (i-ZnO) window layer. The short-circuit current of the former solar cells improved with the reduction in light loss caused by using a thinner ZnO window layer with a wider band gap. Ultrathin uniform A-ZnO window layers also proved more effective than sputtered i-ZnO layers at improving the open-circuit voltage of the CIGS solar cells, because of the additional buffering effect caused by their semiconducting nature. In addition, because of the precise control of the material structure provided by ALD, CIGS solar cells with A-ZnO window layers exhibited a narrow deviation of photovoltaic properties, advantageous for large-scale mass production purposes.

High efficiency Cu2MnSnS4 thin film solar cells with SnS BSF and CdS ETL layers: A numerical simulation

“…A thinner as less as possible thickness is required to be to allow maximum incident light freely. Nevertheless, a very thinner thickness (>50 nm) may cause a noticeable leakage current [ 44 ]. Therefore, this study's buffer layer thickness changed from 0.01 m to 0.08 μm [ 36 ].…”

Advance Supply of Ag and Ga–Se for Increased Backside Ga and Enhanced Cu(In,Ga)Se2 Solar Cell Efficiency

“…To fabricate the CIGS solar cells, we followed a procedure similar to our previous report . CIGS thin films of approximately 2.3 μm were deposited on molybdenum-coated soda lime glass by coevaporating Cu, In, Ga, and Se via a three-stage process.…”

“…To fabricate the CIGS solar cells, we followed a procedure similar to our previous report. 41 CIGS thin films of approximately 2.3 μm were deposited on molybdenumcoated soda lime glass by coevaporating Cu, In, Ga, and Se via a threestage process. For the ACIGS absorber layer, a 10 nm Ag layer was deposited via DC sputtering onto the Mo back contact before the absorber deposition.…”

Amalgamation of rare-earth neodymium ions with ZnO nanoparticles: extensive investigations into the microstructure and optical properties

“…In addition, ZnO has multifarious intrinsic characteristics, such as high photostability and large electrochemical coupling coefficients, and it is also a strong absorber for the ultraviolet (UV) band, making it appropriate for shortwavelength photonic as well as optoelectronic devices [4][5][6]. It is a viable material owing to its prospective applications in multifaceted tracts such as optical pumping, solar cell windows, gas sensors, field emission displays, pharmaceuticals, and photocatalysis [7][8][9][10][11][12].…”