浏览全部资源
扫码关注微信
南京大学物理学院 固体微结构物理国家重点实验室 电子科学与工程学院, 江苏 南京 210093
收稿日期:2011-08-09,
修回日期:2011-08-31,
网络出版日期:2011-11-22,
纸质出版日期:2011-11-22
移动端阅览
李悰, 徐骏, 林涛, 李伟, 李淑鑫, 陈坤基. 超薄氢化非晶锗膜的结构与光电性质[J]. 发光学报, 2011,32(11): 1165-1170
LI Cong, XU Jun, LIN Tao, LI Wei, LI Shu-xin, CHEN Kun-ji. Structural,Eelectronic and Optical Properties of Ultra-thin Hydrogenated Amorphous Germanium Films[J]. Chinese Journal of Luminescence, 2011,32(11): 1165-1170
李悰, 徐骏, 林涛, 李伟, 李淑鑫, 陈坤基. 超薄氢化非晶锗膜的结构与光电性质[J]. 发光学报, 2011,32(11): 1165-1170 DOI:
LI Cong, XU Jun, LIN Tao, LI Wei, LI Shu-xin, CHEN Kun-ji. Structural,Eelectronic and Optical Properties of Ultra-thin Hydrogenated Amorphous Germanium Films[J]. Chinese Journal of Luminescence, 2011,32(11): 1165-1170 DOI:
通过PECVD制备出了不同厚度的a-Ge∶H膜
采用Raman光谱对样品进行了结构表征
由椭圆偏振光谱仪得到样品的厚度和光学常数
并计算了样品的光学带隙。由变温电导率分析了薄膜的电学输运性质
结果表明
载流子的传输机制为扩展态电导。进而利用变温PL谱研究了薄膜的发光性能
发现其发光峰在1.63 m处;随着膜厚的减小
峰位和峰形都有改变
且强度明显提高。进一步分析发现
随着膜厚的减小非辐射复合跃迁的激活能增大
从而导致辐射复合过程增强。
Ultra-thin hydrogenated amorphous germanium films
with various thickness from 160 nm to 5 nm were grown by plasma enhanced chemical vapor deposition technique. The film structure was characterized by Raman spectroscopy
which exhibited a broad band centered around 280 cm
-1
indicating their amorphous nature. The film thickness and optical properties were evaluated by ellipsometer spectroscopy. The measured thickness was well consistent with the pre-designed value and the optical band gap was about 1 eV which slightly increased with the decrease of film thickness. The temperature dependent conductivity of the films was measured. The electronic transport was believed to occur in the extended-states and the corresponding activation energy is about 0.3~0.4 eV. The light emission in infrared region from the films can be detected at low temperature. The sample for 160 nm had a broad luminescence band which can be divided into two sub-bands centered at 0.78 eV and 0.67 eV
respectively. By decreasing the films thickness less than 10 nm
the luminescence band beaome narrower and only a band at 0.8 eV was observed. It may be due to the relatively more hydrogen in the ultrathin films
which passivated the defect states and suppressed the defect-related luminescence. The non-radiative activation energy increased in ultrathin films suggesting the improved efficiency.
Pavesi L. Silicon-based light sources for silicon integrated circuits [J]. Advances in Optical Technologies, 2008, 2008 :1-12.[2] Xu Jun, Chen Guran, Song Chao, et al. Formation and properties of high density Si nanodots [J]. Applied Surface Science, 2010, 256 (18):5691-5694.[3] Yu Wei, Xu Huanqin, Xu Yanmei, et al. Surface oxidation and photoluminescence properties of silicon nanoparticle [J]. Chin. J. Lumin.(发光学报), 2011, 32 (4):347-352 (in Chinese).[4] Chen Yanghua, Li Cheng, Zhou Zhiwen, et al. Room temperature photoluminescence of tensile-strained Ge/Si0.13Ge0.87 quantum wells grown on silicon-based germanium virtual substrate [J]. Appl. Phys. Lett., 2009, 94 (14):141902-1-3.[5] Sun X C, Liu J F, Kimerling L C, et al. Direct gap photoluminescence of n-type tensile-strained Ge-on-Si [J]. Appl. Phys. Lett., 2009, 95 (1):011911-1-3.[6] Peng C S, Huang Q, Cheng W Q, et al. Optical properties of Ge self-organized quantum dots in Si [J]. Phys. Rev. B, 1998, 57 (15):8805-8808.[7] Hemanth J, Michael D, Yoshio N, et al. Nature of germanium nanowire heteroepitaxy on silicon substrates [J]. J. Appl. Phys., 2006, 100 (2):024318-1-10.[8] Brunhes T, Boucaud P, Sauvage S, et al. Electroluminescence of Ge/Si self-assembled quantum dots grown by chemical vapor deposition [J]. Appl. Phys. Lett., 2000, 77 (12):1822-1824.[9] Xia Jinsong, Takeda Yuuki, Usami Noritaka, et al. Room-temperature electroluminescence from Si microdisks with Ge quantum dots [J]. Optics Express, 2010, 18 (13):13945-13950.[10] Ray S K, Das S, Singha R K, et al. Structural and optical properties of germanium nanostructures on Si(100) and embedded in high-k oxides [J]. Nanoscale Research Lett., 2011, 6 (1):224-1-10.[11] Zhang B, Shrestha S, Huang S J, et al. Structural studies of multilayered Ge nanocrystals embedded in SiO2 matrix fabricated using magnetron sputtering [J]. Energy Procedia, 2010, 2 (1):243-250.[12] Chien C Y, Chang Y J, Chang J E, et al. Formation of Ge quantum dots array in layer-cake technique for advanced photovoltaics [J]. Nanotechnology, 2010, 21 (50):505201-1-8.[13] Poulsen P R, Wang Mingxiang, Xu Jun, et al. Role of hydrogen surface coverage during anodic plasma deposition of hydrogenated nanocrystalline germanium [J]. J. Appl. Phys., 1998, 84 (6):3386-3391.[14] Huang Kun, Han Ruqi. Solid State Physics [M]. Beijing: Higher Education Press, 1988:445 (in Chinese).[15] Toyoshima Y, Arai K, Matsuda A, et al. Real time in situ observation of the film growth of hydrogenated amorphous silicon by infrared reflection absorption spectroscopy [J]. Appl. Phys. Lett., 1990, 56 (16):1540-1542.[16] Drsedau T, Schrder B. Optimization of process parameter for the deposition of improved a-Ge∶H by DC magnetron sputtering [J]. J. Appl. Phys., 1994, 75 (6):2864-2875.[17] Chen K J. A Brief Introduction of Amorphous Semiconductor Physics [M]. Beijing: International Academic Publishers, 1987:139 (in Chinese).[18] Fang R C. Solid State Spectroscopy [M]. Hefei: University of Science and Technology of China Press, 2003:200 (in Chinese).[19] Collins R W, William P. Model for the temperature dependence of photoluminescence in a-Si∶H and related materials [J]. Phys. Rev. B, 1982, 25 (8):5257-5262.[20] Li Hui, He Tao, Dai Longgui, et al. Photoluminescence of GeSi self-assembled quantum dots grown by gas source MBE [J]. Chin. J. Lumin.(发光学报), 2011, 32 (8):789-792 (in Chinese).
0
浏览量
192
下载量
2
CSCD
关联资源
相关文章
相关作者
相关机构