Electrical and Optical Properties of n-Type Indium-Doped CdTe/Mg_0.46Cd_0.54Te Double Heterostructures

Journal Article · Mon Jan 18 00:00:00 EST 2016 · IEEE Journal of Photovoltaics

DOI:https://doi.org/10.1109/JPHOTOV.2016.2514742· OSTI ID:1579863

Zhao, Xin-Hao ^[1]; Liu, Shi ^[1]; Zhao, Yuan ^[1]; Campbell, Calli M. ^[1]; Lassise, Maxwell B. ^[1]; Kuo, Ying-Shen ^[1]; Zhang, Yong-Hang ^[1]

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1. Arizona State Univ., Tempe, AZ (United States)

CdTe/Mg_0.46 Cd_0.54 Te double heterostructures with n-type In doping concentrations, varied from 1 × 10¹⁶ to 7 × 10¹⁸ cm^-3, have been grown on InSb substrates using molecular beam epitaxy. Secondary ion mass spectroscopy measurements show strong diffusion of In from the InSb substrate to the CdTe buffer layer, while the In concentration is constant in the CdTe layer between the two Mg_0.46 Cd_0.54 Te barrier layers. Capacitance–voltage measurements show that the dopants are 100% ionized for the doping concentration range from 1 × 10¹⁶ to 1 × 10¹⁸ cm^-3. Additionally, the carrier lifetime decreases with increasing doping concentration (from 0.73 μs for an unintentionally doped sample to 0.74 ns for a 1 × 10¹⁸ cm^-3 doped sample) due to the decrease of both radiative and nonradiative lifetimes. Decent carrier lifetimes are achieved (~100 ns) between 1 × 10¹⁶ and 1 × 10¹⁷ cm^-3 doping levels, which is beneficial for developing n-type monocrystalline CdTe solar cells, photodetectors, and other optoelectronic devices. Lastly, the strongest photoluminescence intensity is observed when the doping concentration is 1 × 10¹⁷ cm^-3, which corresponds to the highest internal quantum efficiency.

• Research Organization: Stanford Univ., CA (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
• Grant/Contract Number: EE0004946; AC36-08GO28308
• OSTI ID: 1579863
• Journal Information: IEEE Journal of Photovoltaics, Vol. 6, Issue 2; ISSN 2156-3381
• Publisher: IEEE
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
14 SOLAR ENERGY
Carrier lifetime
CdTe
doping
MgxCd1-xTe
molecular beam epitaxy (MBE)
solar cells