High temperature transport characteristics of unintentionally doped GaN have been investigated by means of high temperature Hall measurements from room temperature to 500^o C. The increment of electron concentration f...High temperature transport characteristics of unintentionally doped GaN have been investigated by means of high temperature Hall measurements from room temperature to 500^o C. The increment of electron concentration from room temperature to 500^o C is found to vary largely for different samples. The dispersion of temperature dependence of electron concentration is found to be directly proportional to the density of dislocations in GaN layers calculated by fitting the FWHM of the rocking curves in x-ray diffraction measurements （XRD）. The buildup levels in persistent photoconductivity （PPC） are also shown to be directly proportionM to the density of dislocations. The correlation of XRD, Hall and PPC results indicate that the high temperature dependence of electron density in unintentional doped GaN is directly dislocation related.展开更多
这篇扎记的主要意图是说明中国现代民间音乐,听起它的音调总象是多了一个升号(a key with one sharp more than it sounds)。这种类型的曲调,大部分是五声音阶的。从西方音乐的观点来看,它们的调性是受到旋律的倾向,即围绕在哪个或哪几...这篇扎记的主要意图是说明中国现代民间音乐,听起它的音调总象是多了一个升号(a key with one sharp more than it sounds)。这种类型的曲调,大部分是五声音阶的。从西方音乐的观点来看,它们的调性是受到旋律的倾向,即围绕在哪个或哪几个音上的情况为转移,而不是由于在音阶上各音出现的次数来确定的。现以著名的《茉莉花》一曲来说明:展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 60325413 and 60628402, the National Basic Research Programme of China under Grant Nos 2006CB604908 and 2006CB921607, the Cultivation Fund of the Key Scientific and Technical Innovation Project of the Ministry of Education of China （No 705002）, the Research Fund for the Doctoral Programme of Higher Education in China （20060001018）, and the Beijing Natural Science Foundation （No 4062017）.
文摘High temperature transport characteristics of unintentionally doped GaN have been investigated by means of high temperature Hall measurements from room temperature to 500^o C. The increment of electron concentration from room temperature to 500^o C is found to vary largely for different samples. The dispersion of temperature dependence of electron concentration is found to be directly proportional to the density of dislocations in GaN layers calculated by fitting the FWHM of the rocking curves in x-ray diffraction measurements （XRD）. The buildup levels in persistent photoconductivity （PPC） are also shown to be directly proportionM to the density of dislocations. The correlation of XRD, Hall and PPC results indicate that the high temperature dependence of electron density in unintentional doped GaN is directly dislocation related.
文摘这篇扎记的主要意图是说明中国现代民间音乐,听起它的音调总象是多了一个升号(a key with one sharp more than it sounds)。这种类型的曲调,大部分是五声音阶的。从西方音乐的观点来看,它们的调性是受到旋律的倾向,即围绕在哪个或哪几个音上的情况为转移,而不是由于在音阶上各音出现的次数来确定的。现以著名的《茉莉花》一曲来说明:
