Electrical and deep levels characteristics of ZnO/Si heterostructure by MOCVD deposition

ZnO films have been prepared on p-type Si substrates by metal-organic chemical vapour deposition (MOCVD) at different total gas flow rates. The current versus voltage and temperature ($I-V-T$) characteristics, the deep-level transient spectroscopy (DLTS) and the photoluminescence (PL) spectra of the samples were measured. DLTS shows two deep-level centres of $E_1$ ($E_{\rm C}$--0.13$\pm ZnO films have been prepared on p-type Si substrates by metal-organic chemical vapour deposition (MOCVD) at different total gas flow rates. The current versus voltage and temperature ($I-V-T$) characteristics, the deep-level transient spectroscopy (DLTS) and the photoluminescence (PL) spectra of the samples were measured. DLTS shows two deep-level centres of $E_1$ ($E_{\rm C}$--0.13$\pm ZnO films have been prepared on p-type Si substrates by metal-organic chemical vapour deposition (MOCVD) at different total gas flow rates. The current versus voltage and temperature ($I-V-T$) characteristics, the deep-level transient spectroscopy (DLTS) and the photoluminescence (PL) spectra of the samples were measured. DLTS shows two deep-level centres of $E_1$ ($E_{\rm C}$--0.13$\pm ZnO films have been prepared on p-type Si substrates by metal-organic chemical vapour deposition (MOCVD) at different total gas flow rates. The current versus voltage and temperature ($I-V-T$) characteristics, the deep-level transient spectroscopy (DLTS) and the photoluminescence (PL) spectra of the samples were measured. DLTS shows two deep-level centres of $E_1$ ($E_{\rm C}$--0.13$\pm $0.02\,eV) and $E_2$ ($E_{\rm C}$--0.43$\pm $0.05\,eV) in sample 1202a, which has a ZnO/p-Si heterostructure. A deep level at $E_{\rm C}$--0.13$\pm $0.01\,eV was also obtained from the $I-T$ characteristics. It was considered to be the same as $E_1$ obtained from DLTS measurement. The emission related to this deep level center was detected by PL spectra. In addition, the energy location and the relative trap density of $E_1$ was varied when the total gas flow rate was changed.