Optical and surface probe investigation of secondary phases in Cu 2 ZnSnS 4 films grown by electrochemical deposition

Kim, Gee Yeong; Jo, William; Lee, Kee Doo; Choi, Hee Su; Kim, Jin Young; Shin, Hyunik; Nguyen, Trang; Yoon, Seokhyun; Joo, Beom Soo; Gu, Minseon; Han, Mei

doi:10.1016/j.solmat.2015.03.003

Cited by 26 publications

(8 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…High equipment cost for large area deposition of thin films has made vacuum‐based approaches a poor choice. On the other hand, nonvacuum‐based fabrication methods such as chemical bath deposition, electrodeposition, spray pyrolysis, sol‐gel method, spin coating, dip coating, and SILAR have the advantage of economic and environmental cost.…”

Section: Introductionmentioning

confidence: 99%

A review on growth optimization of spray pyrolyzed Cu ₂ ZnSnS ₄ chalcogenide absorber thin film

et al. 2019

View full text Add to dashboard Cite

Summary The progress of solar cell technology in the development of clean and economic quaternary compound copper zinc tin sulfide (CZTS)‐based absorber thin films using the spray pyrolysis technique are presented in this review. CZTS (Cu2ZnSnS4) is the only potential competitor for the existing solar thin film absorbing materials owing to its environment‐friendly Earth abundant constituents. Even though different nonvacuum thin film technologies have been developed for the large area fabrication of this nontoxic absorber material, spray pyrolysis technique offers more versatility in changing the process parameters which has a direct impact on the cell efficiency. It can be used for depositing a wide variety of materials even with complex composition with good crystallinity, and the method has the advantage of being flexible and straightforward to design and can be quickly adopted for extensive area deposition. A survey on the effects of experimental conditions as well as the nature of precursors on the structural, morphological, electrical, and optical properties on the spray pyrolyzed CZTS thin films is discussed in detail. This analysis certainly could provide a potential to obtain new insights in the fabrication of high‐efficiency CZTS‐based solar cells and to launch it into the commercial market to satisfy the ever‐growing future energy demand.

show abstract

Section: Introductionmentioning

confidence: 99%

A review on growth optimization of spray pyrolyzed Cu ₂ ZnSnS ₄ chalcogenide absorber thin film

et al. 2019

View full text Add to dashboard Cite

show abstract

“…KPFM done on reactively co-sputtered films of CZTS and CZTSSe clearly demonstrated that there exists a higher, positive surface potential at the grain boundaries and this finding was correlated with conducting AFM data showing a higher current in these same regions [26]; another study on CZTS films grown by the same method showed using conducting AFM and KPFM that the photocurrent primarily flowed along grain boundaries and capacitance microscopy [27] was used to show that the charge separation takes place at the interface of the grain boundary and grain and the current predominantly moved along these boundaries [28,29]. KPFM has also been used to detect the presence of unwanted secondary phases on the surface of CZTS films by KCN-etching [30] as well as in CZTSSe by depth profiling [31].…”

Section: Introductionmentioning

confidence: 99%

A low-cost, sulfurization free approach to control optical and electronic properties of Cu2ZnSnS4 via precursor variation

Gupta

Whittles

Batra

et al. 2016

Solar Energy Materials and Solar Cells

View full text Add to dashboard Cite

Thin films of Cu2ZnSnS4 (CZTS) were synthesized via a low cost, wet chemical technique of chemical bath deposition (CBD). In the first part of this study, the chemical composition ratio S/(Cu+Zn+Sn) was varied keeping Cu/(Zn + Sn) and Zn/Sn ratios constant to study the effect of sulfur variation. Detailed electrical and optical characterization has been carried out using UV-Vis spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy, Raman spectroscopy and Kelvin probe force microscopy (KPFM) techniques. The results of the present study confirm that near ideal stoichiometry could be achieved in CZTS by adding excess thiourea in a controlled manner which eliminates the need for the normally used post-synthesis and high temperature sulfurization step. Using the stoichiometric sample as the basis, in the second part of the study Cu/(Zn+Sn) and Zn/Sn was varied and it was found that the electronic properties of CZTS in terms of band gap, work function and valence band edge position could be controlled by precursor variation. The Cu-poor, Zn-rich samples showed a better photoresponse which has been attributed to a decrease in the CuZn type defects. The study thus demonstrates a scalable and low-cost technique to grow CZTS absorber layers for solar cells with control over its electronic properties which is important for effective device operation.

show abstract

“…The work functions of the two‐step‐sulfurized CIGSSe thin films with different sulfur concentrations were calculated by comparing the work functions of the tip and the sample. The work function of the sample (ϕ sample ) was obtained by subtracting the tip work function (ϕ tip ) and by using highly‐oriented pyrolytic graphite , though its value is affected by the doping and carrier concentration . V CPD is the contact potential difference of the tip and the sample, and e is the elementary charge.…”

Section: Resultsmentioning

confidence: 99%

High photo-conversion efficiency in double-graded Cu(In,Ga)(S,Se)₂thin film solar cells with two-step sulfurization post-treatment

Kim

Yang

Nguyen

et al. 2016

Prog. Photovolt: Res. Appl.

Self Cite

View full text Add to dashboard Cite

Sulfur is extensively used to increase the bandgap of Cu(In,Ga)(S,Se)2 (CIGSSe) solar cells and to improve the open circuit voltage (VOC) in order to optimize the characteristics of the devices. This study uses a sulfurization process to obtain a double‐graded bandgap profile. Selenization was carried out on Cu(In,Ga) precursors, followed by one sulfurization process or two consecutive sulfurization processes on top of the CIGSe absorber layer surface. The optimum two‐step sulfurization process provides an increase of VOC of 0.05 V and an improvement of conversion efficiency of 1.17%. The efficiency of the 30 × 30 cm2 monolithic module, which has 64 CIGS cells connected in series (aperture area: 878.6 cm2), is 15.85%. The optical and electrical properties of the phase and the work function distribution were investigated using the depth profiles of the absorber layer as a function of the sulfurization conditions. The CIGSSe thin film formed by two‐step sulfurization with a high sulfur concentration exhibits a single work function peak, better crystallinity, and higher conversion efficiency than those of the thin film formed by two‐step sulfurization at low sulfur concentration. In terms of the Raman spectra depth profile, the phase areas for the CIGSSe thin film that underwent the optimized high sulfur concentration two‐step‐sulfurization appeared to have less of Cu2‐xSe phase than that with low sulfur concentration. Consequently, surface and interface phase analysis is an essential consideration to improve cell efficiency. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

show abstract

Optical and surface probe investigation of secondary phases in Cu 2 ZnSnS 4 films grown by electrochemical deposition

Cited by 26 publications

References 51 publications

A review on growth optimization of spray pyrolyzed Cu ₂ ZnSnS ₄ chalcogenide absorber thin film

A review on growth optimization of spray pyrolyzed Cu ₂ ZnSnS ₄ chalcogenide absorber thin film

A low-cost, sulfurization free approach to control optical and electronic properties of Cu2ZnSnS4 via precursor variation

High photo-conversion efficiency in double-graded Cu(In,Ga)(S,Se)₂thin film solar cells with two-step sulfurization post-treatment

Contact Info

Product

Resources

About

Optical and surface probe investigation of secondary phases in Cu 2 ZnSnS 4 films grown by electrochemical deposition

Cited by 26 publications

References 51 publications

A review on growth optimization of spray pyrolyzed Cu 2 ZnSnS 4 chalcogenide absorber thin film

A review on growth optimization of spray pyrolyzed Cu 2 ZnSnS 4 chalcogenide absorber thin film

A low-cost, sulfurization free approach to control optical and electronic properties of Cu2ZnSnS4 via precursor variation

High photo-conversion efficiency in double-graded Cu(In,Ga)(S,Se)2thin film solar cells with two-step sulfurization post-treatment

Contact Info

Product

Resources

About

A review on growth optimization of spray pyrolyzed Cu ₂ ZnSnS ₄ chalcogenide absorber thin film

A review on growth optimization of spray pyrolyzed Cu ₂ ZnSnS ₄ chalcogenide absorber thin film

High photo-conversion efficiency in double-graded Cu(In,Ga)(S,Se)₂thin film solar cells with two-step sulfurization post-treatment