【摘要】 用ZnO陶瓷靶,采用脉冲激光沉积(PLD)技术在c-Al2O3衬底上制备了ZnO薄膜。通过不同温度下光致发光(PL)光谱的测量,对样品的紫外发光机理进行研究。在较低温度(10 K)下的PL光谱中,观测到一个位于3.354 eV处的束缚激子(D0X)发射,随着温度的升高(～50 K),在D0X的高能侧观测到了自由激子的发射峰。在10 K温度下,3.309 eV处出现了一个较强的发光带A,此发光带强度随着温度升高先增大然后减小,并且一直延续到室温。重点讨论了此发光带的起源,并认为A带可归属于自由电子-受主之间的复合发射。更多还原

【Abstract】 High orientated undoped ZnO thin films were prepared on c-Al2O3 substrates by pulsed laser deposition(PLD) method and using ZnO ceramic target as resource material.The photoluminescence(PL) origin of the ZnO thin films was discussed in detailed.PL spectrum of ZnO thin films is dominated by donor-bound exciton(D0X)emission at low temperatures while the free exciton transition(FX) gradually dominates the spectrum at higher temperatures.It notes that one emission band A at around 3.309 eV(T=10 K) can be clearly observed with increase in temperature up to room temperature.The mechanism of this emission band was investigated by the temperature dependence of PL spectra.The results can be attributed to the transition of conduction band electrons to acceptors(e,A0),in which the acceptor binding energy was approximately 129 meV.However,the formation mechanism of the acceptor states need be investigated further.更多还原