Details

Autor(en) / Beteiligte

• Mishima, T D
• Santos, M B
• Cheng, Y
• Whiteside, V R
• Sellers, I R
• Hossain, K
• Laghumavarapu, R B
• Liang, B L
• Huffaker, D L

Titel

High-density InAs/GaAs1−xSbx quantum-dot structures grown by molecular beam epitaxy for use in intermediate band solar cells

Ist Teil von

• Journal of applied physics, 2016-03, Vol.119 (11)

Ort / Verlag

Melville: American Institute of Physics

Erscheinungsjahr

2016

Quelle

American Institute of Physics (AIP) Journals

Beschreibungen/Notizen

• InAs quantum-dot structures were grown using a GaAs1−xSbx matrix on a GaAs(001) substrate. The use of GaAs1−xSbx for the buffer and cap layers effectively suppressed coalescence between dots and significantly increased the dot density. The highest density (∼3.5 × 1011/cm2) was obtained for a nominal 3.0 monolayer deposition of InAs with an Sb composition of x = 13–14% in the GaAs1−xSbx matrix. When the Sb composition was increased to 18%, the resulting large photoluminescent red shift (∼90 meV) indicated the release of compressive strain inside the quantum dots. For x > 13%, we observed a significant decrease in photoluminescence intensity and an increase in the carrier lifetime (≥4.0 ns). This is attributed to the type-II band alignment between the quantum dots and matrix material.