Mechanisms of extrinsic alkali incorporation in CIGS solar cells on flexible polyimide elucidated by nanoscale and quantitative analyses

Kim, Kihwan; Jeong, Inyoung; Cho, Yunae; Shin, Donghyeop; Song, Soomin; Ahn, Seung Kyu; Eo, Young-Joo; Cho, Ara; Jung, Chanwon; Jo, William; Kim, Jihun; Choi, Pyuck‐Pa; Gwak, Jihye; Yun, Jae Ho

doi:10.1016/j.nanoen.2019.104201

Cited by 39 publications

(57 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Then, temperature‐dependent current–voltage measurement was applied on the samples with Ag deposition durations of 0, 0.5, 1, 2, and 4 min to explore the changed V oc of solar cells, and the corresponding results are provided in Figure a–e. The relationship between V oc and J sc is given by [ 29,31,34,50–52 ]

V_{OC} = \frac{E_{a}}{q} - \frac{A k T}{q} \ln (\frac{J_{00}}{J_{SC}})

where E a is the activation energy of the recombination, T is the temperature, and A is the diode quality factor. J 00 is the temperature‐dependent prefactor, which is only determined by T .…”

Section: Resultsmentioning

confidence: 99%

“…Chalcopyrite Cu(In,Ga)Se 2 (CIGS) is one of the most intriguing absorbers due to its high efficiencies above 23%, [ 1 ] potentially being utilized in the large‐area roll‐to‐roll process. [ 2–4 ] Highly efficient CIGS‐based solar cells possess a multilayer stacked structure, which includes a p‐type CIGS absorber layer, an n‐type buffer layer (CdS or Zn(O,S)), and a transparent conductive oxide (TCO: ZnO and aluminum (Al)‐doped ZnO). [ 5–7 ] In consequence, interface engineering of the CIGS‐based solar cell plays a critical role in the improvement of device performance, particularly for the CdS/CIGS heterojunction interface.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Silver Surface Treatment of Cu(In,Ga)Se₂ (CIGS) Thin Film: A New Passivation Process for the CdS/CIGS Heterojunction Interface

Zhang

Lin

et al. 2020

Solar RRL

View full text Add to dashboard Cite

The interface engineering of Cu(In,Ga)Se2 (CIGS)‐based solar cells is challenging for high‐efficiency devices, especially for the CdS/CIGS heterojunction interface. Recently, post‐treatment of the CIGS surface, as an efficient approach to passivate the defects at the CdS/CIGS interface, has attracted widespread attention. Here, a simple Ag surface treatment process is used to realize the passivation of interface defects and the enhancement of the CdS/CIGS heterojunction. This process not only reduces the surface roughness of CIGS films significantly, but also contributes to controlling the Ga composition in the surface layer. Furthermore, characterization techniques reveal that Ag surface treatment can effectively decrease the defect concentrations at the heterojunction interface and enhance the CdS/CIGS heterojunction quality with appropriate Ag deposition duration. Further investigations on the changed defect level caused by the Ag surface treatment indicate that the increased defect level is likely related to the shift of valence band maximum. Eventually, the efficiency of the optimum device has a relative increase of about 18% compared with that of the reference solar cell. This work focuses on revealing the differences of the CIGS surface and CdS/CIGS interface caused by Ag, which provides a new surface processing method for the passivation of the CdS/CIGS heterojunction.

show abstract

V_{OC} = \frac{E_{a}}{q} - \frac{A k T}{q} \ln (\frac{J_{00}}{J_{SC}})

where E a is the activation energy of the recombination, T is the temperature, and A is the diode quality factor. J 00 is the temperature‐dependent prefactor, which is only determined by T .…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Silver Surface Treatment of Cu(In,Ga)Se₂ (CIGS) Thin Film: A New Passivation Process for the CdS/CIGS Heterojunction Interface

Zhang

Lin

et al. 2020

Solar RRL

View full text Add to dashboard Cite

show abstract

“…Given that high-quality films possess compact and large-grained morphologies with suitable Cu-poor and Zn-rich compositions, the required growth temperatures to enable device-quality CZTSe films prepared by one-step method seem to be in the temperature range of 380~480 °C, as depicted in Figure 2c,h. The poor film coverage with island grains and unfavorable chemical composition could be The typical device structure for high-efficiency CIGS and CZTSSe PVs was employed throughout the studies [17,20]. A 60-nm-thick CdS buffer layer (n-type) was deposited on the CZTSe/Mo/SLG by using chemical bath deposition (CBD).…”

Section: Resultsmentioning

confidence: 99%

“…The entire temperature profile for the CZTSe film deposition is given as shown in Figure 1. The typical device structure for high-efficiency CIGS and CZTSSe PVs was employed throughout the studies [17,20]. A 60-nm-thick CdS buffer layer (n-type) was deposited on the CZTSe/Mo/SLG by using chemical bath deposition (CBD).…”

Section: Methodsmentioning

confidence: 99%

Fabrication and Characterization of Cu2ZnSnSe4 Thin-Film Solar Cells using a Single-Stage Co-Evaporation Method: Effects of Film Growth Temperatures on Device Performances

et al. 2020

Self Cite

View full text Add to dashboard Cite

Kesterite-structured Cu2ZnSnSe4 (CZTSe) is considered as one of the Earth-abundant and non-toxic photovoltaic materials. CZTSe films have been prepared using a single-step co-evaporation method at a relatively low temperature (i.e., below 500 °C). Due to the volatile nature of tin-selenide, the control over substrate temperature (i.e., growth temperature) is very important in terms of the deposition of high-quality CZTSe films. In this regard, the effects of growth temperatures on the CZTSe film morphology were investigated. The suitable temperature range to deposit CZTSe films with Cu-poor and Zn-rich compositions was 380–480 °C. As the temperature increased, the surface roughness of the CZTSe film decreased, which could improve p/n junction properties and associated device performances. Particularly, according to capacitance-voltage (C-V) and derived-level capacitance profiling (DLCP) measurements, the density of interfacial defects of CZTSe film grown at 480 °C showed the lowest value, of the order of ~3 × 1015 cm−3. Regardless of applied growth temperatures, the formation of a MoSe2 layer was rarely observed, since the growth temperature was not high enough to have a reaction between Mo back contact layers and CZTSe absorber layers. As a result, the photovoltaic (PV) device with CZTSe film grown at 480 °C yielded the best power conversion efficiency of 6.47%. It is evident that the control over film growth temperature is a critical factor for obtaining high-quality CZTSe film prepared by one-step process.

show abstract

“…The incorporation of alkali elements into the CIGS solar cells has led to two step‐changes: greatly improved bulk quality by Na doping developed in the 1990s, and surface passivation by heavy alkali postdeposition treatment (PDT) developed recently. [ 9,59,95–98 ] Na doping for CIGS has been proven effective in passivating charge compensating donor‐like defects such as In Cu and Ga Cu , thus significantly improving the minority carrier lifetime and effective p‐type doping. [ 99,100 ] The heavy alkali based chalcopyrites such as KInSe 2 , RbInSe 2 , and CsInSe 2 formed by PDT are effective epitaxial surface passivation layers, which also allow for a thinner CdS buffer layer and an associated reduction in photocurrent loss caused by parasitic absorption.…”

Section: Alkali Treatments In Kesterite Solar Cellsmentioning

confidence: 99%

Kesterite Solar Cells: Insights into Current Strategies and Challenges

et al. 2021

View full text Add to dashboard Cite

Earth‐abundant and environmentally benign kesterite Cu2ZnSn(S,Se)4 (CZTSSe) is a promising alternative to its cousin chalcopyrite Cu(In,Ga)(S,Se)2 (CIGS) for photovoltaic applications. However, the power conversion efficiency of CZTSSe solar cells has been stagnant at 12.6% for years, still far lower than that of CIGS (23.35%). In this report, insights into the latest cutting‐edge strategies for further advance in the performance of kesterite solar cells is provided, particularly focusing on the postdeposition thermal treatment (for bare absorber, heterojunction, and completed device), alkali doping, and bandgap grading by engineering graded cation and/or anion alloying. These strategies, which have led to the step‐change improvements in the power conversion efficiency of the counterpart CIGS solar cells, are also the most promising ones to achieve further efficiency breakthroughs for kesterite solar cells. Herein, the recent advances in kesterite solar cells along these pathways are reviewed, and more importantly, a comprehensive understanding of the underlying mechanisms is provided, and promising directions for the ongoing development of kesterite solar cells are proposed.

show abstract

Mechanisms of extrinsic alkali incorporation in CIGS solar cells on flexible polyimide elucidated by nanoscale and quantitative analyses

Cited by 39 publications

References 45 publications

Silver Surface Treatment of Cu(In,Ga)Se₂ (CIGS) Thin Film: A New Passivation Process for the CdS/CIGS Heterojunction Interface

Silver Surface Treatment of Cu(In,Ga)Se₂ (CIGS) Thin Film: A New Passivation Process for the CdS/CIGS Heterojunction Interface

Fabrication and Characterization of Cu2ZnSnSe4 Thin-Film Solar Cells using a Single-Stage Co-Evaporation Method: Effects of Film Growth Temperatures on Device Performances

Kesterite Solar Cells: Insights into Current Strategies and Challenges

Contact Info

Product

Resources

About

Mechanisms of extrinsic alkali incorporation in CIGS solar cells on flexible polyimide elucidated by nanoscale and quantitative analyses

Cited by 39 publications

References 45 publications

Silver Surface Treatment of Cu(In,Ga)Se2 (CIGS) Thin Film: A New Passivation Process for the CdS/CIGS Heterojunction Interface

Silver Surface Treatment of Cu(In,Ga)Se2 (CIGS) Thin Film: A New Passivation Process for the CdS/CIGS Heterojunction Interface

Fabrication and Characterization of Cu2ZnSnSe4 Thin-Film Solar Cells using a Single-Stage Co-Evaporation Method: Effects of Film Growth Temperatures on Device Performances

Kesterite Solar Cells: Insights into Current Strategies and Challenges

Contact Info

Product

Resources

About

Silver Surface Treatment of Cu(In,Ga)Se₂ (CIGS) Thin Film: A New Passivation Process for the CdS/CIGS Heterojunction Interface

Silver Surface Treatment of Cu(In,Ga)Se₂ (CIGS) Thin Film: A New Passivation Process for the CdS/CIGS Heterojunction Interface