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GaTlAs Quantum Well Solar Cells for Sub-band Gap Absorption

Published online by Cambridge University Press:  27 August 2019

Ahmed Zayan  and
Thomas E. Vandervelde
Ahmed Zayan
Affiliation:
Renewable Energy and Applied Photonics Laboratory, Electrical and Computer Engineering Department Tufts University Medford, Massachusetts02155, USA
Thomas E. Vandervelde*
Affiliation:
Renewable Energy and Applied Photonics Laboratory, Electrical and Computer Engineering Department Tufts University Medford, Massachusetts02155, USA
*
*[email protected]
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Abstract

Despite the improvements seen in efficiency of GaAs cells over the years, there remains room for improvement for it to approach the theoretical single junction limit posited by Shockley and Quiesser decades ago. One of the more pursued options is the growth of quantum wells within the structure of GaAs to enhance its photon absorption below its bandgap. Multiple Quantum Wells (MQW) have been an ongoing topic of research and discussion for the scientific community with structures like InGaAs/GaAs and InGaP/GaAs quantum wells producing promising results that could potentially improve overall energy conversion. Here, we used WEIN2K, a commercial density functional theory package, to study the ternary compound Ga1-xTlxAs and determine its electronic properties. Using these results combined with experimental confirmation we extend these properties to simulate its application to form a MQW GaAs/ Ga1-xTlxAs solar cell. Ga1-xTlxAs is a tunable ternary compound, with its bandgap being strongly dependent on the concentration of Tl present. Concentrations of Tl as low as 7% can reduce the bandgap of Ga1-xTlxAs to roughly 1.30 eV from GaAs’s 1.45 eV at room temperature with as little as a 1.7% increase in lattice constant. The change in bandgap, accompanied by the relatively small change in lattice constant makes Ga1-xTlxAs a strong candidate for a MQW cell with little to no strain balancing required within the structure to minimize unwanted defects that impede charge collection within the device. Our GaAs photodiode with TlGaAs MQWs shows an expanded absorption band and improved conversion efficiency over the standard GaAs photovoltaic cell with dilute concentrations of Tl incorporated into the compound.

Keywords

photovoltaicTlsimulation
Type
Articles
Information
MRS Advances , Volume 4 , Issue 36: Energy and Sustainability , 2019 , pp. 2015 - 2021
Copyright
Copyright © Materials Research Society 2019 

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References

REFERENCES

Connolly, J. P. et al., “Optimisation of High Efficiency AlxGa1-xAs MQW Solar Cells {[}arXiv],” in arXiv, 2016, no. October 2018, p. 12 pp.Google Scholar
Ohtsuka, H., Kitatani, T., Yazawa, Y., and Warabisako, T., “Numerical prediction of InGaAs/GaAs MQW solar cell characteristics under concentrated sunlight,” Sol. Energy Mater. Sol. Cells, vol. 50, no. 1–4, pp. 251–257, 1998.CrossRefGoogle Scholar
Dahal, R., Pantha, B., Li, J., Lin, J. Y., and Jiang, H. X., “InGaN/GaN multiple quantum well solar cells with long operating wavelengths,” Appl. Phys. Lett., vol. 94, no. 6, pp. 2009–2011, 2009.CrossRefGoogle Scholar
Watanabe, N., Mitsuhara, M., Yokoyama, H., Liang, J., and Shigekawa, N., “Influence of InGaN/GaN multiple quantum well structure on photovoltaic characteristics of solar cell,” Jpn. J. Appl. Phys., vol. 53, no. 11, pp. 1–9, 2014.CrossRefGoogle Scholar
Roberts, J. S. et al., “Photovoltaic characterisation of GaAsBi/GaAs multiple quantum well devices,” Sol. Energy Mater. Sol. Cells, vol. 172, no. July, pp. 238–243, 2017.Google Scholar
Mazouz, H. M. A., Belabbes, A., Zaoui, A., and Ferhat, M., “First-principles study of lattice dynamics in thallium-V compounds,” Superlattices Microstruct., vol. 48, no. 6, pp. 560–568, 2010.CrossRefGoogle Scholar
Van Schilfgaarde, M., Chen, A. B., Krishnamurthy, S., and Sher, A., “InTlP - A proposed infrared detector material,” Appl. Phys. Lett., vol. 65, no. 21, pp. 2714–2716, 1994.CrossRefGoogle Scholar
Krishnamurthy, S., Chen, A. B., Sher, A., and Sher, A., “Near band edge absorption spectra of narrowgap III–V semiconductor alloys,” vol. 4045, 1996.CrossRefGoogle Scholar
Takushima, M. et al., “Thallium incorporation during TlInAs growth by low-temperature MBE,” J. Cryst. Growth, vol. 301–302, no. SPEC. ISS., pp. 117–120, 2007.CrossRefGoogle Scholar
Kajikawa, Y., Kobayashi, N., and Terasaki, H., “Limits in growing TlGaAs/GaAs quantum-well structures by low-temperature molecular-beam epitaxy,” Mater. Sci. Eng. B Solid-State Mater. Adv. Technol., vol. 126, no. 1, pp. 86–92, 2006.CrossRefGoogle Scholar
Kajikawa, Y. et al., “Effect of Tl content on the growth of TlGaAs films by low-temperature molecular-beam epitaxy,” J. Appl. Phys., vol. 93, no. 3, pp. 1409–1416, 2003.CrossRefGoogle Scholar
Schwarz, K. and Blaha, P., “Solid state calculations using WIEN2k,” vol. 28, pp. 259–273, 2003.CrossRefGoogle Scholar
Tran, F., Laskowski, R., Blaha, P., and Schwarz, K., “Performance on molecules, surfaces, and solids of the Wu-Cohen GGA exchange-correlation energy functional,” Phys. Rev. B, vol. 75, no. 115131, pp. 1–14, 2007.CrossRefGoogle Scholar
Asahi, H., Koh, H., Takenaka, K., Asami, K., Oe, K., and Gonda, S., “Gas source MBE growth and characterization of TlInGaP and TlInGaAs layers for long wavelength applications,” vol. 202, pp. 1069–1072, 1999.Google Scholar
Asahi, H., Koh, H., Takenaka, K., Asami, K., Oe, K., and Gonda, S., “Gas source MBE growth and characterization of TlInGaP and TlInGaAs layers for long wavelength applications,” J. Cryst. Growth, vol. 201, pp. 1069–1072, 1999.CrossRefGoogle Scholar
Arakawa, Y., Sakaki, H., Nishioka, M., Yoshino, J., and Kamiya, T., “Recombination lifetime of carriers in GaAs-GaAlAs quantum wells near room temperature,” Appl. Phys. Lett., vol. 46, no. 5, pp. 519–521, 1985.CrossRefGoogle Scholar
Mukhtarova, A. et al., “Dependence of the photovoltaic performance of pseudomorphic InGaN/GaN multiple-quantum-well solar cells on the active region thickness,” Appl. Phys. Lett., vol. 108, no. 16, 2016.CrossRefGoogle Scholar