C-axis oriented Ga-doped ZnO(GZO) films with various thicknesses were deposited on glass substrate by radio frequency(RF) magnetron sputtering. The dependence of crystal structure,electrical,and optical properties of ...C-axis oriented Ga-doped ZnO(GZO) films with various thicknesses were deposited on glass substrate by radio frequency(RF) magnetron sputtering. The dependence of crystal structure,electrical,and optical properties of the GZO films on crystalline size were systematically studied. The results showed that the texture coefficient of (002) peak (TC(002)) decreases with increasing crystalline size. The Hall mobility m was reciprocal to electron effective mass and the fitted relaxation time s was 0.11±0.01 ms. With the increase of average crystalline size,the resistivity increased slightly,which is caused by the competition of (002) and(101) plane,introducing in some defects and leading to carrier density reduction. The optical band gap was in the range from 3.454 to 3.319 eV with increasing crystalline size from 26.96 to 30.88 nm,showing a negative relationship. The dependence of optical band gap (Eopg) on the crystalline size(R) can be qualitatively explained by a quantum confinement effect. The relationship between Eopg and R of GZO films suggests that tuning up optical properties for desired applications can be achieved by controlling the crystalline size.展开更多
An 8μm thick Ga-doped ZnO（GZO） film grown by metal-source vapor phase epitaxy was deposited on a GaN-based light-emitting diode（LED） to substitute for the conventional ITO as a transparent conduct layer（TCL）. E...An 8μm thick Ga-doped ZnO（GZO） film grown by metal-source vapor phase epitaxy was deposited on a GaN-based light-emitting diode（LED） to substitute for the conventional ITO as a transparent conduct layer（TCL）. Electroluminescence spectra exhibited that the intensity value of LED emission with a GZO TCL is markedly improved by 23.6%as compared to an LED with an ITO TCL at 20 mA.In addition,the forward voltage of the LED with a GZO TCL at 20 mA is higher than that of the conventional LED.To investigate the reason for the increase of the forward voltage,X-ray photoelectron spectroscopy was performed to analyze the interface properties of the GZO/p-GaN heterojunction.The large valence band offset（2.24±0.21 eV） resulting from the formation of Ga_2O_3 in the GZO/p-GaN interface was attributed to the increase of the forward voltage.展开更多
基金supported by the National Natural Science Foundation of China (No.51071038)Sichuan Province Science Foundation for Youths (No.2010JQ0002)State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,China (No.20131309)
文摘C-axis oriented Ga-doped ZnO(GZO) films with various thicknesses were deposited on glass substrate by radio frequency(RF) magnetron sputtering. The dependence of crystal structure,electrical,and optical properties of the GZO films on crystalline size were systematically studied. The results showed that the texture coefficient of (002) peak (TC(002)) decreases with increasing crystalline size. The Hall mobility m was reciprocal to electron effective mass and the fitted relaxation time s was 0.11±0.01 ms. With the increase of average crystalline size,the resistivity increased slightly,which is caused by the competition of (002) and(101) plane,introducing in some defects and leading to carrier density reduction. The optical band gap was in the range from 3.454 to 3.319 eV with increasing crystalline size from 26.96 to 30.88 nm,showing a negative relationship. The dependence of optical band gap (Eopg) on the crystalline size(R) can be qualitatively explained by a quantum confinement effect. The relationship between Eopg and R of GZO films suggests that tuning up optical properties for desired applications can be achieved by controlling the crystalline size.
文摘An 8μm thick Ga-doped ZnO（GZO） film grown by metal-source vapor phase epitaxy was deposited on a GaN-based light-emitting diode（LED） to substitute for the conventional ITO as a transparent conduct layer（TCL）. Electroluminescence spectra exhibited that the intensity value of LED emission with a GZO TCL is markedly improved by 23.6%as compared to an LED with an ITO TCL at 20 mA.In addition,the forward voltage of the LED with a GZO TCL at 20 mA is higher than that of the conventional LED.To investigate the reason for the increase of the forward voltage,X-ray photoelectron spectroscopy was performed to analyze the interface properties of the GZO/p-GaN heterojunction.The large valence band offset（2.24±0.21 eV） resulting from the formation of Ga_2O_3 in the GZO/p-GaN interface was attributed to the increase of the forward voltage.
