Tuning zinc doping content to optimize optical and structural properties of Cd_1−xZn_xS buffer layers

Abstract

In this paper, Cd_1−xZn_xS thin films were prepared by chemical bath deposition (CBD), and the effects of different zinc doping content on the morphological structure and optical properties of Cd_1−xZn_xS buffer layers are systematically discussed. The experimental results show that in the deposition process of different substrates, the crystal structure of the film is all hexagonal, and when the concentration of zinc sulfate (ZnSO₄) precursor is varied from 0 to 0.025 M, the films are uniform and dense. With the increase of zinc content, the X-ray diffraction (XRD) peak of the films shifted behind that of CdS film (002). It showed 70% to 90% transmittance in the visible region and the optical band gap increased gradually. The band gap value of the films obtained ranged from 2.43 eV to 3.01 eV. It shows the potential feasibility of its application to photovoltaic devices.

References

[1] GödeF, ÜnlüS. Synthesis and characterization of CdS window layers for PbS thin film solar cells[J]. Materials science in semiconductor processing, 2019, 90: 92-100

[2] ShabanH, GadS A, MansourB A, et al.. The influence of substrate temperatures and thickness on optical and electrical conductivity of CuIn(Se_0.25S_0.75)₂[J]. Journal of inorganic and organometallic polymers and materials, 2020, 30(4):1360-1368

[3] WangL, XueY, WangZ, et al.. Effects of ammonia concentration on morphology, composition and optical properties of ZnO_1−xS_x thin films of Cu(In,Ga)Se₂ solar cells[J]. Optoelectronics letters, 2022, 18(4):0215-0221

[4] BarmanB, BangeraK V, ShivakumarG K. A comprehensive study on the structural, morphological, compositional and optical properties of Zn_xCd_1−xS thin films[J]. Materials research express, 2020, 6(12):126441

[5] MariappanR, RagavendarM, PonnuswamyV. Growth and characterization of chemical bath deposited Cd_1−xZn_xS thin films[J]. Journal of alloys and compounds, 2011, 509(27): 7337-7343

[6] BaykulM C, OrhanN. Band alignment of Cd_1−xZn_xS produced by spray pyrolysis method[J]. Thin solid films, 2010, 518(8):1925-1928

[7] PatidarD, SaxenaN S, SharmaT P. Structural, optical and electrical properties of CdZnS thin films[J]. Journal of modern optics, 2008, 55(1):79-88

[8] ErturkK, IsikM, TerlemezogluM, et al.. Optical and structural characteristics of electrodeposited Cd_1−xZn_xS nanostructured thin films[J]. Optical materials, 2021, 114: 110966

[9] ZellaguiR, DehdouhH, AdnaneM, et al.. Cd_xZn_1−xS thin films deposited by chemical bath deposition (CBD) method[J]. Optik, 2020, 207: 164377

[10] MunnaF T, SelvanathanV, SobayelK, et al.. Diluted chemical bath deposition of CdZnS as prospective buffer layer in CIGS solar cell[J]. Ceramics international, 2021, 47(8):11003-11009

[11] LilhareD, KhareA. Effect of annealing on structural, morphological and optical properties of CdTe/(Cd−Zn)S thin films[J]. IOP conference series: materials science and engineering, 2020, 798(1):012022

[12] LiuX, JiangY, FuF, et al.. Facile synthesis of high-quality ZnS, CdS, CdZnS, and CdZnS/ZnS core/shell quantum dots: characterization and diffusion mechanism[J]. Materials science in semiconductor processing, 2013, 16(6): 1723-1729

[13] XUE Y, WANG X, ZHANG L, et al. Chemical bath deposition of Cd_1−xZn_xS as buffer layer in CIGS solar cell[J]. Distributed generation & alternative energy journal, 2022: 401–418.

[14] ZhangL, XueY, FengS, et al.. Influence of ammonia concentration on the structural, composition and optical properties of CdZnS thin films[J]. Materials science in semiconductor processing, 2019, 104: 104650

[15] PurohitA, PatelS L, ChanderS, et al.. Substrate evolution to microstructural and optoelectrical properties of evaporated CdS thin films correlated with elemental composition[J]. Acta metallurgica sinica (English letters), 2021, 34(9):1307-1316

[16] MunnaF T, ChelvanathanP, SobayelK, et al.. Effect of zinc doping on the optoelectronic properties of cadmium sulphide (CdS) thin films deposited by chemical bath deposition by utilizing an alternative sulphur precursor[J]. Optik, 2020, 218: 165197

[17] ZhangX, ChenJ, ChenJ, et al.. Synthesis of CdZnS buffer layer and its impact on Cu₂ZnSn(S,Se)₄ thin film solar cells[J]. Journal of materials science: materials in electronics, 2022, 33(5):2399-2405

[18] SunS, GuoJ, HaoR, et al.. Influence of Cd_0.6Zn_0.4S buffer layer on the band alignment and the performance of CZTS thin film solar cells[J]. Optical materials, 2021, 112: 110666

[19] XueY, ZhangS, SongD, et al.. Effect of concentration of cadmium sulfate solution on structural, optical and electric properties of Cd_1−xZn_xS thin films[J]. Journal of semiconductors, 2021, 42(11): 112101

[20] HossainT, SobayelM K, MunnaF T, et al.. Tuning the bandgap of Cd_1−xZn_xS (x=0∼1) buffer layer and CIGS absorber layer for obtaining high efficiency[J]. Superlattices and microstructures, 2022, 161: 107100