Photoexcitation screening of the built-in electric field in ZnO single quantum wells
- WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)
- Cross-Correlated Materials Research Group (CMRG), Advanced Science Institute (ASI), RIKEN, Wako 351-0198 (Japan)
- Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)
ZnO/Mg{sub 0.22}Zn{sub 0.78}O quantum wells were studied by excitation-intensity-dependent luminescence at 10 K. The samples were grown by laser molecular-beam epitaxy on ScAlMgO{sub 4} substrates to evaluate the well width dependence (1 to 10 nm) of exciton transition energies. Under weak excitation, the photoluminescence shows a quantum-confined Stark effect for the wide wells. The well width dependences of the experimental transition energies are compared with previously reported calculations to evaluate the electric field due to spontaneous and piezoelectric polarizations. The internal electric field is comparable with 650 kV/cm. With an increase in excitation intensity, blueshift of the luminescence was observed, suggesting photoexcitation screening of electric fields.
- OSTI ID:
- 21175605
- Journal Information:
- Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 12 Vol. 93; ISSN APPLAB; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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