Doping levels, trap density of states and the performance of co-doped CdTe(As,Cl) photovoltaic devices

Proskuryakov, Y. Y.; Durose, K.; Major, Jonathan D.; Turkestani, M. K. Al; Barrioz, Vincent; Irvine, S.J.C.; Jones, Eurig W.

doi:10.1016/j.solmat.2009.04.010

Cited by 48 publications

(28 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This was attributed to segregation of As at the grain boundaries, interfaces, back surface or at defects within the CdTe layer. 10,56 This correlated 56 with a decrease in shunt resistance as As concentration was increased from 1 Â 10 17 to 1.5 Â 10 19 atoms cm À3 . Nevertheless, acceptor concentration levels achieved $10 15 cm À3 and, if doping concentrations are optimised, then group V elements such as As and Sb can be used as effective dopants to form p-type CdTe.…”

Section: Extrinsicmentioning

confidence: 80%

“…Too much dopant material can cause issues by segregating in the grain boundaries along which they diffuse to the junction producing shunting pathways. 4,24,56 Diffusion of Sb has been observed 46,57 to be slower in CdTe than Cu aer stability tests were carried out with assessment of PV degradation in solar cells with different back contact materials.…”

Section: Extrinsicmentioning

confidence: 99%

“…55,56 The As Te shallow acceptor is also an important p-type dopant for CdTe as it only requires a low formation energy of 1.68 eV ensuring an effective doping. 58 A study 56 using capacitance-voltage (C-V) measurements found that As dopant concentration in CdTe of PV solar cells grown by MOCVD was several orders of magnitude greater than the acceptor concentration.…”

Section: Extrinsicmentioning

confidence: 99%

“…Cd-rich conditions 55,56 are used to promote As incorporation into Te vacancies and excessive deep donor V Te must be avoided. An As-dopant concentration of 2 Â 10 18 atoms cm À3 was found 55,56 to give the optimum dopant levels in order to obtain the p-type conduction, while increasing the As-dopant concentrations [As] above this value resulted in reduced solar cell performance. The likely reason for the drop in efficiency with increased [As] beyond a value of 2 Â 10 18 atoms cm À3 is increased segregation of As into the grain boundaries, which may then diffuse towards the junction creating localised areas of high electrical conduction leading to micro-shorts and increased shunting.…”

Section: Mocvd Cdte:as Absorber and Contact Layermentioning

confidence: 99%

See 3 more Smart Citations

Thin Film Cadmium Telluride Solar Cells

Clayton

Barrioz

2014

Materials Challenges

View full text Add to dashboard Cite

This chapter discusses a number of deposition techniques used to produce polycrystalline CdTe solar cells, including progress of photovoltaic (PV) performances in recent years. Focus is on the CdTe absorber and the effects from impurities, which are dependent on the process conditions used, but also due to self-compensating nature of the material itself influencing the acceptor levels in the layer. Impurities can introduce deep donor/acceptor levels that act as traps for both majority and minority carriers. This leads to greater recombination and reduced carrier lifetimes, causing a loss in the level of generated photocurrent and overall performance of the PV cell. Impurities are typically concentrated at the CdTe grain boundaries, making grain size an important parameter for defect density control. Post-growth treatment using CdCl2 and annealing improves PV performances in several ways: grain re-crystallisation and growth; inter-diffusion at the CdS–CdTe interface removing defects related to the lattice mismatch between the two layers; and passivation of deep acceptor states through complex formation with the ClTe+ shallow donor. High p-type doping is necessary for the formation of a back contact with good ohmic properties without a Schottky barrier restricting conduction of majority carriers. Stable back contacts are also required, with the Sb2Te3–Mo system possibly offering the best solution. Finally MOCVD is presented as a prospective technique for large-scale industrial production of CdTe solar modules, with discussion of the beneficial impact in reducing CdTe absorber thickness and the processing challenges associated with it.

show abstract

Section: Extrinsicmentioning

confidence: 80%

Section: Extrinsicmentioning

confidence: 99%

Section: Extrinsicmentioning

confidence: 99%

Section: Mocvd Cdte:as Absorber and Contact Layermentioning

confidence: 99%

See 2 more Smart Citations

Thin Film Cadmium Telluride Solar Cells

Clayton

Barrioz

2014

Materials Challenges

View full text Add to dashboard Cite

show abstract

“…In order to reduce the bulk recombination and the cost of solar cells manufacturing for optimal performance, a research in n-CdS/p-CdTe thin films has been started [6]. Both CdTe and CdS are quite stable and can be produced using various scalable techniques like Chemical Both Deposition, Close-space sublimation, Molecular Organic Chemical Vase Deposition (MOCVD), Atomic Layer Epitaxy (ALE), screen printing, sputtering, sintering, Molecular Beam Epitaxy (MBE), Electro-deposition (ED) and High Vacuum Evaporation (HVE) [7]- [9].…”

Section: Introductionmentioning

confidence: 99%

Optimization of Electrics Parameters CdS/CdTe Thin Film Solar Cell Using Dielectric Model

Niasse¹,

Tankari²,

Dia³

et al. 2016

WJCMP

View full text Add to dashboard Cite

In this paper, the electrical properties of heterojunction solar cells thin film n-CdS/p-CdTe from dielectric model have been studied. Based on the expression of the minority, carriers density in the p-CdTe base of solar cell, the photocurrent density and that of the photo voltage are determined according to the cell dimensions, doping levels, the absorption coefficient, the solar irradiance and the temperature, etc. Fitting using Mathcad and Origin Lab software on the photocurrent and the photovoltage of the n-CdS/p-CdTe enabled to determine the series, shunt resistance and the maximum power point. The results obtained, in good agreement with experimental results, allow operating simulations for optimizing maximum outputs parameters (I p , V p ). Thereafter, it is proposed a type of photovoltaic generator module with a good command of the design parameters for better efficiency.

show abstract

Defect and Contact Passivation for Perovskite Solar Cells

2019

View full text Add to dashboard Cite

Metal‐halide perovskites are rapidly emerging as an important class of photovoltaic absorbers that may enable high‐performance solar cells at affordable cost. Thanks to the appealing optoelectronic properties of these materials, tremendous progress has been reported in the last few years in terms of power conversion efficiencies (PCE) of perovskite solar cells (PSCs), now with record values in excess of 24%. Nevertheless, the crystalline lattice of perovskites often includes defects, such as interstitials, vacancies, and impurities; at the grain boundaries and surfaces, dangling bonds can also be present, which all contribute to nonradiative recombination of photo‐carriers. On device level, such recombination undesirably inflates the open‐circuit voltage deficit, acting thus as a significant roadblock toward the theoretical efficiency limit of 30%. Herein, the focus is on the origin of the various voltage‐limiting mechanisms in PSCs, and possible mitigation strategies are discussed. Contact passivation schemes and the effect of such methods on the reduction of hysteresis are described. Furthermore, several strategies that demonstrate how passivating contacts can increase the stability of PSCs are elucidated. Finally, the remaining key challenges in contact design are prioritized and an outlook on how passivating contacts will contribute to further the progress toward market readiness of high‐efficiency PSCs is presented.

show abstract

Doping levels, trap density of states and the performance of co-doped CdTe(As,Cl) photovoltaic devices

Cited by 48 publications

References 33 publications

Thin Film Cadmium Telluride Solar Cells

Thin Film Cadmium Telluride Solar Cells

Optimization of Electrics Parameters CdS/CdTe Thin Film Solar Cell Using Dielectric Model

Defect and Contact Passivation for Perovskite Solar Cells

Contact Info

Product

Resources

About