Fabrication of high performance nano-crystalline germanium films using ultra-clean ECR plasma CVD

使用超净 ECR 等离子体 CVD 制备高性能纳米晶锗薄膜

基本信息

批准号：
12650325
负责人：
AOKI Takeshi
金额：
$ 1.98万
依托单位：
TOKYO INSTITUTE OF POLYTECHNICS
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650325/
关键词：
nanocrystal amorphous microcrystal photoluminescence lifetime Germanium CVD ECR Plasma エピタキシャル励起子優先配向 ECR

项目摘要

Hydrogenated microcrystalline germanium (μc-Ge : H) films were deposited on crystalline (c-) Si, c-Ge and glass substrates by electron-cyclotron-resonance plasma chemical vapor deposition (ECRPCVD). With increasing substrate temperature (Ts), an amorphous to microcrystalline phase transition started at Ts 【approximately equal】 50 ℃. Above 200 ℃, the crystalline volume fraction (_<Xc>) on the c-Si and Ge substrates exceeded 【approximately equal】 80% and preferential growth of μc-Ge : H along crystallographic axes of the substrates was observed. For the glass substrates, _<Xc> was a maximum at 【approximately equal】 155 ℃, above which it decreased with increasing T_s. Hydrogen desorption from the growth surface is probably responsible for suppressing microciystalline nucleation. The PL peak energy and magnitude decreased with increasing T_s, but PL spectrum even at T_s = 313 ℃ being broad compared with that of c-Ge suggest the PL arises from the amorphous part of the grain boundary.High-quality hydrogenated amorphous germanium (a-Ge : H) films were deposited under the critical condition of the film growth of amorphous-crystalline phase transition. Double-peak lifetime distribution were observed in a-Ge : H. A dual-phase double lock-in (DPDL) quadrature frequency resolved spectroscopy (QFRS) developed to measure ns lifetime with a newly devised semi-analytical deconvolution revealed that the PL lifetime distribution is basically double-peaked in chalcogenide as well as tetrahedral semiconductors such as a-Si : H and a-Ge : H. The short lived (ns-μs) and the long lived (ms) components are attributed singlet and triplet excitons, respectively. We proposed that controlling spin states of electron-hole pairs is a key to prolong the recombination lifetime and improve the device-quality e.g. efficiency of solar cells.

通过电子循环蛋白晶体晶体胶片（c-）Si，C-GE和玻璃底物，通过电子环体 - 循环量子体等离子体化学蒸气沉积（ECRPCVD），将氢化的微晶（μCGE：H）膜沉积在晶体（C-）Si，C-GE和玻璃底物上。随着底物温度（TS）的升高，在TS [大约等于] 50°的无定形至微晶相变。观察到了C-SI和GE底物上的结晶体积分数（_ <xc>）超过[大约等于] 80％，并且沿底物的晶体学轴的首选生长：H沿底物的晶体学轴。对于玻璃基板，_ <xc>在[大约等于] 155°的最大值中是最大值，而在t_s上增加了它的降低。从生长表面解吸的氢可能是导致抑制微囊稳定核化的原因。与C-GE相比，PL峰值能量和大小随T_S的增加而降低，但即使在T_S = 313℃时，PL频谱也很广泛，这表明PL源于晶界的无定形部分。在膜的关键条件下，高质量的氢化无形晶属（A-GE：H）膜沉积在膜成长的关键状态下，是在反斑层中的膜成长的膜生长。 Double-peak lifetime distribution were observed in a-Ge : H. A dual-phase double lock-in (DPDL) quadrature frequency resolved spectroscopy (QFRS) developed to measure ns lifetime with a newly devised semi-analytical deconvolution revealed that the PL lifetime distribution is basically double-peaked in chalcogenide as well as tetrahedral semiconductors such as a-Si : H and a-Ge : H.短期寿命（NS-μs）和长期寿命（MS）组件分别归因于Singlet和Triplet激子。我们提出，控制电子孔对的自旋状态是延长重组寿命并改善设备质量的关键。太阳能电池的效率。