Pressure Behaviour of the UV and Green Emission Bands in ZnO Micro-rods
The pressure behavior of the ultraviolet (UV) and green emission bands in ZnO tetrapod-like micro-rods has been investigated at 300 and 70 K, respectively. The pressure coefficient of the UV band at 300 K is 24.5 meV/GPa, consistent with that of the band gap of bulk ZnO. However, the pressure coefficient of the green band is 25 meV/GPa, far larger than previous literature reports. The green band in this work comes originates from Cu-related emission, as confirmed by the fine structure observed in the spectra at 10 K. The pressure coefficients of four pho-non replicas of the free exciton emission (FX) at 70 K are 21.0, 20.2, 19.8, and 19.3 meV/GPa, respectively. The energy shift rate of the FX emission and the LO phonon energies is then determined to be 21.4 and 0.55 meV/GPa. The pressure coefficient of the neutral donor bound exciton (D0X) transition is 20.5 meV/GPa, only 4% smaller than that of FX. This confirms that the D0X emission corresponds to excitons bound to neutral shallow donors.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 900915
- Report Number(s):
- PNNL-SA-51536; 2214a; KP1303000
- Journal Information:
- Physica Status Solidi B, Basic Research, 244(1):87-92, Journal Name: Physica Status Solidi B, Basic Research, 244(1):87-92 Journal Issue: 1 Vol. 244
- Country of Publication:
- United States
- Language:
- English
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