Title :
Exploration of epitaxial quantum dots within wide band gap metamorphic host materials for intermediate band solar cells
Author :
Grassman, Tyler J. ; Shah, D.B. ; Carlin, John A. ; Ringel, Steven A.
Author_Institution :
Dept. of Mater. Sci. & Eng., Ohio State Univ., Columbus, OH, USA
Abstract :
The use of metamorphic (lattice-mismatched) host materials for the growth of Stranski-Krastanov type epitaxial quantum dots (QDs) is explored. Two alloys that provide access to wide band gaps (up to and above 2.0 eV), GaAsP and InGaP, are considered and compared to their lattice-matched analogs. InGaAs/GaAsP QD/host structures are found to yield smaller and denser QDs, with a stronger photoluminescence (PL) blue-shift, than the equally-strained lattice-matched InGaAs/GaAs system. Metamorphic InP/InGaP QDs are found to appear nearly identical to the lattice-matched analogs, but do exhibit a slightly larger PL blue-shift. Results indicate the potential for using metamorphic substrates to provide additional tailoring of QD properties, in addition to providing access to QD/host materials combinations that are more consistent with intermediate band solar cell design requirements.
Keywords :
III-V semiconductors; gallium arsenide; indium compounds; photoluminescence; semiconductor quantum dots; solar cells; spectral line shift; wide band gap semiconductors; InGaAs-GaAsP; InP-InGaP; QD properties; Stranski-Krastanov type epitaxial quantum dots; intermediate band solar cells; lattice-matched analogs; metamorphic lattice-mismatched host materials; metamorphic quantum dots; metamorphic substrates; photoluminescence blue-shift; wide band gap metamorphic host materials; wide band gaps; Gallium arsenide; Indium phosphide; Photonic band gap; Photovoltaic cells; Quantum dots; Substrates; III-V semiconductor materials; epitaxial layers; photoluminescence; photovoltaic cells; quantum dots;
Conference_Titel :
Photovoltaic Specialists Conference (PVSC), 2013 IEEE 39th
Conference_Location :
Tampa, FL
DOI :
10.1109/PVSC.2013.6744148