Photoluminescence study of Cu diffusion and electromigration in CdTe

Grecu, D.; Compaan, A.

doi:10.1063/1.124375

Cited by 83 publications

(41 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This observation demonstrates that the doped Cu had formed Cu + − V Cd complexes and/or Cu Cd states, indicating that the doped Cu, or at least part of the doped Cu in CdS, had taken the lattice positions of Cd vacancies. 16 The decreased V Cd -related emission intensity with increased Cu doping, indicated by the arrow in Fig. 6(a), showed that during the CBD deposition Cu atoms/ions adopted the V Cd lattice sites.…”

Section: Resultsmentioning

confidence: 99%

“…[12][13][14][15] It was reported that Cu doping of CdTe absorber layer could lead to Cu diffusion to the CdTe/CdS interface. 16 In a solar cell structure, accumulation of Cu near the CdS/CdTe junction interface would have profound influence on the cell performance. Recombination centers and electric shunting paths may be introduced near the junction area, which is the most essential part in a cell device.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Cu-doped CdS and its application in CdTe thin film solar cell

Deng

Yang

et al. 2016

AIP Advances

View full text Add to dashboard Cite

Cu is widely used in the back contact formation of CdTe thin film solar cells. However, Cu is easily to diffuse from the back contact into the CdTe absorber layer and even to the cell junction interface CdS/CdTe. This phenomenon is generally believed to be the main factor affecting the CdTe solar cell stability. In this study Cu was intentionally doped in CdS thin film to study its effect on the microstructural, optical and electrical properties of the CdS material. Upon Cu doping, the VCd− and the surface-state-related photoluminescence emissions were dramatically decreased/quenched. The presence of Cu atom hindered the recrystallization/coalescence of the nano-sized grains in the as-deposited CdS film during the air and the CdCl2 annealing. CdTe thin film solar cell fabricated with Cu-doped CdS window layers demonstrated much decreased fill factor, which was induced by the increased space-charge recombination near the p-n junction and the worsened junction crystalline quality. Temperature dependent current-voltage curve measurement indicated that the doped Cu in the CdS window layer was not stable at both room and higher temperatures.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Cu-doped CdS and its application in CdTe thin film solar cell

Deng

Yang

et al. 2016

AIP Advances

View full text Add to dashboard Cite

show abstract

“…The latter matches the best activation levels in recent samples incorporated with As during molecular beam epitaxy or P during Bridgman growth, where the lifetime increased with activation. 12,49 Cu has been observed to increase lifetime at low concentration and can replace defects such as Te Cd or V Cd , as observed in PL spectra by Grecu et al 10,21 At larger Cu concentrations, lifetime has been observed to decrease. 10,50,51 The severe lifetime reduction by Cu shown in Fig.…”

Section: 15mentioning

confidence: 72%

“…19,20 After the Te anneal, a 1.54-1.55-eV peak emerges in the low-temperature PL data that have been identified as a donor-acceptor pair (DAP) transition involving an acceptor Cd-vacancy complex. [21][22][23][24] 116102 When samples are annealed in Te with Cu present, Cu can occupy Cd sites to form Cu Cd acceptors. Effective-mass theory calculations indicate that the Cu Cd level is 146-147 meV, and they accurately describe transition energies measured by infrared absorption between many Cu Cd states such as 1S 3/2 to 2P 5/2 (Γ 7 ).…”

Section: 15mentioning

confidence: 99%

Carrier density and lifetime for different dopants in single-crystal and polycrystalline CdTe

et al. 2016

View full text Add to dashboard Cite

CdTe defect chemistry is adjusted by annealing samples with excess Cd or Te vapor with and without extrinsic dopants. We observe that Group I (Cu and Na) elements can increase hole density above 1016 cm−3, but compromise lifetime and stability. By post-deposition incorporation of a Group V dopant (P) in a Cd-rich ambient, lifetimes of 30 ns with 1016 cm−3 hole density are achieved in single-crystal and polycrystalline CdTe without CdCl2 or Cu. Furthermore, phosphorus doping appears to be thermally stable. This combination of long lifetime, high carrier concentration, and improved stability can help overcome historic barriers for CdTe solar cell development.

show abstract

“…One, which occurs at forward bias, is Cu-related, field-driven, occurs iñ hours, greatly increases the recombination, and is partially reversible with field [57,62]. A second mechanism leads to formation of a blocking contact, which also occurs rapidly and is likely related to loss of Cu, but is not reversible with field.…”

Section: Phenomenological Model and Conclusionmentioning

confidence: 99%

Optimization of Processing and Modeling Issues for Thin Film Solar Cell Devices Including Concepts for the Development of Polycrystalline Multijunctions Annual Subcontract Report, 24 August 1999 - 23 August 2000

Birkmire¹,

Phillips²,

Shafarman³

et al. 2001

View full text Add to dashboard Cite

SUMMARYThe overall mission of the Institute of Energy Conversion (IEC) is the development of thin film photovoltaic cells, modules, and related manufacturing technology and the education of students and professionals in photovoltaic technology. The objectives of this 12 month NREL subcontract are to advance the state of the art and the acceptance of thin film PV solar cells in the areas of improved technology for thin film depositions, device fabrication, and material and device characterization and modeling, relating to solar cells based on CuInSe2 and its alloys, on doped and intrinsic microcrystalline Si films, and on CdTe. CuInSe 2 -BASED SOLAR CELLS In-line Evaporation of Cu(InGa)Se 2In-line evaporation is a potentially effective means to achieve the high rate uniform deposition necessary for commercial-scale manufacture of Cu(InGa)Se 2 modules. In this process, the substrate is linearly translated over thermal sources from which the elemental materials are evaporated.An in-line evaporation system for the deposition of Cu(InGa)Se 2 films has been put into operation at IEC. The system's performance in terms of uniform deposition over large areas at relatively high rates and in terms of device performance and reproducibility has been successfully demonstrated. The compositional uniformity across the 6-inch wide deposition zone is within the uncertainty limits of EDS measurements. A set of depositions with translation speeds ranging from 1 to 2.5 inches/min produced films with thicknesses from 2.1 to 0.9 µm. Devices from these runs had efficiencies from 13.2-14.5 %, for thickness > 1 µm, demonstrating the run-to-run reproducibility of the system. The best cell produced with Cu(InGa)Se 2 from this in-line system had 14.9% efficiency. Effect of Deposition Temperature on Cu(InGa)Se 2 Films and DevicesOne means to reduce manufacturing costs for thin film Cu(InGa)Se 2 is by reducing the substrate temperature at which the Cu(InGa)Se 2 layer is deposited. The effect of substrate temperature on the film grain size, morphology, and compositional uniformity and device performance of Cu(InGa)Se 2 deposited at 480°C was characterized and compared to previous results at 400°C and 550°C. At 480°C, the soda lime glass substrate is below the strain point of the glass, reducing handling problems.Cu(InGa)Se 2 films were deposited by multisource elemental evaporation with different deposition sequences to determine the effect of a Cu-rich growth step, i.e., deposition with the Cu molar flux greater than the sum of the In and Ga fluxes. The grain size was determined from atomic force microscopy images. The films deposited at 480°C have comparable grain size and morphology to those deposited at 550°C. However, V oc , FF, and efficiency of devices with films deposited at 550°C were greater. A Cu-rich growth step during the deposition does not affect the measured grain size or device performance at these temperatures. The films deposited at 400°Ciii have smaller grains and poorer device performance. At this lower temperature the Cu-...

show abstract

Photoluminescence study of Cu diffusion and electromigration in CdTe

Cited by 83 publications

References 18 publications

Cu-doped CdS and its application in CdTe thin film solar cell

Cu-doped CdS and its application in CdTe thin film solar cell

Carrier density and lifetime for different dopants in single-crystal and polycrystalline CdTe

Optimization of Processing and Modeling Issues for Thin Film Solar Cell Devices Including Concepts for the Development of Polycrystalline Multijunctions Annual Subcontract Report, 24 August 1999 - 23 August 2000

Contact Info

Product

Resources

About