Diffusion and incorporation of Cd in solar-grade Cu(In,Ga)Se2 layers

Hiepko, K.; Bastek, J.; Schlesiger, Ralf; Schmitz, Guido; Wuerz, Roland; Stolwijk, N. A.

doi:10.1063/1.3665036

Cited by 34 publications

(40 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[10][11] Moreover, it is worthy of notice that CIGS tandem solar cells are subjected to heat treatment during fabrication of the top cell (e.g. CuGaSe 2 ).…”

mentioning

confidence: 99%

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se₂ Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing

Kim

et al. 2015

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

We selected a sputtered-Zn(O,S) film as a buffer material and fabricated a Cu(In,Ga)Se2 (CIGS) solar cell for use in monolithic tandem solar cells. A thermally stable buffer layer was required because it should withstand heat treatment during processing of top cell. Postannealing treatment was performed on a CIGS solar cell in vacuum at temperatures from 300-500 °C to examine its thermal stability. Serious device degradation particularly in VOC was observed, which was due to the diffusion of thermally activated constituent elements. The elements In and Ga tend to out-diffuse to the top surface of the CIGS, while Zn diffuses into the interface of Zn(O,S)/CIGS. Such rearrangement of atomic fractions modifies the local energy band gap and band alignment at the interface. The notch-shape induced at the interface after postannealing could function as an electrical trap during electron transport, which would result in the reduction of solar cell efficiency.

show abstract

“…[10][11] Moreover, it is worthy of notice that CIGS tandem solar cells are subjected to heat treatment during fabrication of the top cell (e.g. CuGaSe 2 ).…”

mentioning

confidence: 99%

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se₂ Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing

Kim

et al. 2015

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…CISbased diffusion studies report higher volume diffusion activation energies values of 1.19 eV and 1.3 eV with an extreme outlier value of 0.47 eV [4][5]. Assuming that the cadmium volume diffusion activation energy of 1.04 eV (acquired by Hiepko et al for CIGS material) is a good approximation and that the data acquired from the CIGS samples that were polished for 40 minutes and annealed for 1 hour are the most representative of cadmium diffusion in CIGS, the grain boundary diffusion activation energy can be estimated to be on the order of 0.74 eV.…”

Section: E Estimated Cadmium Diffusion Activation Energiesmentioning

confidence: 99%

Diffusion activation energy of cadmium in thin film CuInGaSe<inf>2</inf>

Biderman

Novak

Laursen

et al. 2013

2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)

View full text Add to dashboard Cite

Diffusivity and activation energy of cadmium in copper indium gallium diselenide (CuInGaSe 2 or CIGS) thin films were investigated by annealing solar-grade SLG/Mo/CIGS/CdS samples of two different CIGS thicknesses at temperatures between 150° C and 325° C. Diffusion profiles of cadmium volume and grain boundary were investigated by dualbeam time-of-flight secondary ion mass spectroscopy. A relationship between the cadmium's volume and grain boundary diffusion coefficients and their activation energies at a given annealing temperature was established using LeClaire's grain boundary diffusion model. The data also provide evidence that cadmium diffusion may be strongly modulated by a gallium gradient seen both laterally at the interface and in the bulk in solar-grade CIGS material.

show abstract

“…The second stage cadmium diffusion profiles show that cadmium has almost the same Arrhenius diffusion equation as iron in CIGS, implying a similar diffusion mechanism. 4,[24][25][26] In the work done by Hiepko et al, cadmium was indiffused into a copper-poor CIGS thin film from an elemental source at a high annealing temperature and duration such that the cadmium distribution becomes virtually homogenous at all depths with a measured concentration of ∼ 3 at. %.…”

Section: E Evaluation Of Experimental Datamentioning

confidence: 99%

“…%. 24 The 3 at. % figure is assumed to be representative of the second-stage cadmium diffusion in CIGS.…”

Section: E Evaluation Of Experimental Datamentioning

confidence: 99%

“…Now, the simulations are compared to existing diffusion data of zinc, iron, and cadmium in CIGS. 4,[22][23][24][25][26][27] Zinc diffusion profiles offer the strongest evidence of the dissociative diffusion mechanism in CIGS. As discussed in section III C, CIGS:Zn diffusion profiles have two prominent features: 1) Fickian-like humps at the front and back sides and 2) a zinc signal plateau in the middle region.…”

Section: E Evaluation Of Experimental Datamentioning

confidence: 99%

See 1 more Smart Citation

Dissociative diffusion mechanism in vacancy-rich materials according to mass action kinetics

et al. 2016

View full text Add to dashboard Cite

Two sets of diffusion-reaction numerical simulations using a finite difference method (FDM) were conducted to investigate fast impurity diffusion via interstitial sites in vacancy-rich materials such as Cu(In,Ga)Se2 (CIGS) and Cu2ZnSn(S, Se)4 (CZTSSe or CZTS) via the dissociative diffusion mechanism where the interstitial diffuser ultimately reacts with a vacancy to produce a substitutional. The first set of simulations extends the standard interstitial-limited dissociative diffusion theory to vacancy-rich material conditions where vacancies are annihilated in large amounts, introducing non-equilibrium vacancy concentration profiles. The second simulation set explores the vacancy-limited dissociative diffusion where impurity incorporation increases the equilibrium vacancy concentration. In addition to diffusion profiles of varying concentrations and shapes that were obtained in all simulations, some of the profiles can be fitted with the constant- and limited-source solutions of Fick’s second law despite the non-equilibrium condition induced by the interstitial-vacancy reaction. The first set of simulations reveals that the dissociative diffusion coefficient in vacancy-rich materials is inversely proportional to the initial vacancy concentration. In the second set of numerical simulations, impurity-induced changes in the vacancy concentration lead to distinctive diffusion profile shapes. The simulation results are also compared with published data of impurity diffusion in CIGS. According to the characteristic properties of diffusion profiles from the two set of simulations, experimental detection of the dissociative diffusion mechanism in vacancy-rich materials may be possible.

show abstract

Diffusion and incorporation of Cd in solar-grade Cu(In,Ga)Se2 layers

Cited by 34 publications

References 12 publications

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se₂ Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se₂ Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing

Diffusion activation energy of cadmium in thin film CuInGaSe<inf>2</inf>

Dissociative diffusion mechanism in vacancy-rich materials according to mass action kinetics

Contact Info

Product

Resources

About

Diffusion and incorporation of Cd in solar-grade Cu(In,Ga)Se2 layers

Cited by 34 publications

References 12 publications

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se2 Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se2 Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing

Diffusion activation energy of cadmium in thin film CuInGaSe<inf>2</inf>

Dissociative diffusion mechanism in vacancy-rich materials according to mass action kinetics

Contact Info

Product

Resources

About

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se₂ Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing

Photovoltaic Performance and Interface Behaviors of Cu(In,Ga)Se₂ Solar Cells with a Sputtered-Zn(O,S) Buffer Layer by High-Temperature Annealing