First-principles-based analysis of the influence of Cu on CdTe electronic properties

Krasikov, Dmitry; Knizhnik, Andrey A.; Потапкин, Б. В.; Selezneva, Svetlana; Sommerer, Timothy J.

doi:10.1016/j.tsf.2012.10.027

Cited by 44 publications

(31 citation statements)

References 14 publications

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“…Copper is a common dopant used in CdTe solar cells to improve p-type conductivity. First-principle calculations indicate that Cu on a Cd site (Cu’ Cd ) forms deep acceptors [6,7]. However, copper also forms compensating donors on interstitial sites (Cu • i ), and as a result the achievable hole density is limited [6,8].…”

Section: Introductionmentioning

confidence: 99%

Structural and electronic properties of CdTe_1-xSe_x films and their application in solar cells

Lingg

Spescha

Haass

et al. 2018

Science and Technology of Advanced Materials

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The performance improvement of conventional CdTe solar cells is mainly limited by doping concentration and minority carrier life time. Alloying CdTe with an isovalent element changes its properties, for example its band gap and behaviour of dopants, which has a significant impact on its performance as a solar cell absorber. In this work, the structural, optical, and electronic properties of CdTe1-xSex films are examined for different Se concentrations. The band gap of this compound changes with composition with a minimum of 1.40 eV for x = 0.3. We show that with increasing x, the lattice constant of CdTe1-xSex decreases, which can influence the solubility of dopants. We find that alloying CdTe with Se changes the effect of Cu doping on the p-type conductivity in CdTe1-xSex, reducing the achievable charge carrier concentration with increasing x. Using a front surface CdTe1-xSex layer, compositional, structural and electronic grading is introduced to solar cells. The efficiency is increased, mostly due to an increase in the short-circuit current density caused by a combination of lower band gap and a better interface between the absorber and window layer, despite a loss in the open-circuit voltage caused by the lower band gap and reduced charge carrier concentration.

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Section: Introductionmentioning

confidence: 99%

Structural and electronic properties of CdTe_1-xSe_x films and their application in solar cells

Lingg

Spescha

Haass

et al. 2018

Science and Technology of Advanced Materials

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“…Firstly, the expected Cu on Cd site point defect (Cu Cd ) is a deep acceptor, predicted to be positioned between 220 and 310 meV above the valence band by first principle calculations [2,3]. Furthermore, Cu exhibits an amphoteric behavior; while it acts as an acceptor when occupying a Cd site it is a donor when placed at an interstitial position.…”

Section: Introductionmentioning

confidence: 99%

CdTe thin films doped by Cu and Ag - a comparison in substrate configuration solar cells

Gretener

Wyss

Perrenoud

et al. 2014

2014 IEEE 40th Photovoltaic Specialist Conference (PVSC)

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One of the main problems to be solved in order to raise the efficiency of CdTe solar cells is the low acceptor concentration in polycrystalline CdTe layers which is limiting the open circuit voltage. The commonly used acceptor dopant Cu not only forms rather deep acceptor defects but is also likely to limit the net acceptor concentration due to the formation of compensating donor type defects. In this work, Ag is examined as a possible candidate for improving acceptor concentration in CdTe thin films. Hole density in CdTe layers with varying elemental Ag concentration follows a similar trend as previously reported for Cu doping. In finished solar cells efficiencies up to 11.6 % could be reached using Ag as acceptor dopant. Measurements of hole density, barrier height, space charge region width and depth dependent elemental distribution indicate the similarity of the Ag and Cu doping process.

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“…[28][29][30] Electrical device measurements observe many trap levels, and thus, Cu Cd assignments range from 150 to 400 meV. [31][32][33][34] However, for single crystals, correlated Hall, admittance spectroscopy, and PL measurements corroborate the Cu Cd level at 135-157 meV.…”

Section: 15mentioning

confidence: 99%

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

et al. 2016

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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.

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First-principles-based analysis of the influence of Cu on CdTe electronic properties

Cited by 44 publications

References 14 publications

Structural and electronic properties of CdTe_1-xSe_x films and their application in solar cells

Structural and electronic properties of CdTe_1-xSe_x films and their application in solar cells

CdTe thin films doped by Cu and Ag - a comparison in substrate configuration solar cells

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

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First-principles-based analysis of the influence of Cu on CdTe electronic properties

Cited by 44 publications

References 14 publications

Structural and electronic properties of CdTe1-xSex films and their application in solar cells

Structural and electronic properties of CdTe1-xSex films and their application in solar cells

CdTe thin films doped by Cu and Ag - a comparison in substrate configuration solar cells

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

Contact Info

Product

Resources

About

Structural and electronic properties of CdTe_1-xSe_x films and their application in solar cells

Structural and electronic properties of CdTe_1-xSe_x films and their application in solar cells