Abstract
From Raman scattering on a-plane wurtzite ZnO crystals we obtained a decreasing splitting between longitudinal and transversal optical phonons with A1 and E1 symmetry as a function of hydrostatic pressure up to 5.5 GPa. Consequently, the transverse effective charge (e*T) exhibits a strong reduction with increasing pressure, yielding 2.17-14.6× 10-3 P/GPa and 2.04-13.7× 10-3 P/GPa (in units of the elementary charge) for the A1 and E1 phonons, respectively. We find a clear systematic in the linear pressure coefficient of e*T with bond polarity for the series of wide-band gap semiconductors SiC, AlN, GaN, and ZnO. © 2010 American Institute of Physics.
Original language | English |
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Article number | 231906 |
Journal | Applied Physics Letters |
Volume | 96 |
Issue number | 23 |
DOIs | |
Publication status | Published - 18 Jun 2010 |