Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants|
|Research Institution||Tokyo Institute of Technology|
SHIMIZU Isamu Tokyo Inst.Tech.Prof., 大学院・総合理工学研究科, 教授 (40016522)
半那 純一 東京工業大学, 工学部, 教授 (00114885)
FORTMANN C.m. The Pennsylvania State Univ., Assoc.Prof., 電気工学科, 客員教授
WAGNER S. Princeton Univ., Prof., 電気工学科, 教授
WRONSKI C.r. The Pennsylvania State Univ., Prof., 電気工学科, 教授
MATSUDA A. Electrotechnical Laboratries, 非平衡材料, 室長
HAN-NA J. Tokyo Inst.Tech., Prof.
|Project Period (FY)
1993 – 1994
Completed(Fiscal Year 1994)
|Budget Amount *help
¥6,000,000 (Direct Cost : ¥6,000,000)
Fiscal Year 1994 : ¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1993 : ¥3,000,000 (Direct Cost : ¥3,000,000)
|Keywords||a-Si : H / Staebler-Wronski Effect / Chemical Annealing / Charged Defects / Light-induced Degradation / Thin Film / Plasma / アモルファス・シリコン / 安定性 / プラズマCVD|
An International collaborative study for the aim of improvement of amorphous silicon (a-Si : H) has been carried out by six experts ; 3 American and 3 Japanese. We have roughly distinguished our roles into two ; (1) fabrication of a-Si : H and (2) characterization of the optoelectrical properties of the films and devices.Japanese research teams directed by Prof.J.Hanna, Dr.A.Matuda and myself have mainly focused our attentions to the fabrication processes. The research teams in US,on the other hand, have performed the study on the characterization of films and devices.
The group of Tokyo Institute of Technology developed successfully a novel technique called "Chemical Annealing" to fabricate stable a-Si : H with the gaps of 1.8-2.1 eV.In addition, the relaxation process of Si-network induced by permeation of atomic hydrogen was quantitatively analyzed by measuring the surface with an in situ ellipsometry. The ETL group directed by Dr.Matsuda proposed an reliable model of growth kinetics
for accumulation of defects resulting from the reactions at the growing surface, which indicated some efficient ways given the names PADS and DREP for fabrication of high quality a-Si : H.
Princeton Univ.group directed by Prof.Wagner performed a systematic study to reveal the kinetics of light induced defects together with the light-induced annealing effect for a-Si : H.
Consequently, they concluded the defects density at the saturated state were ruled by the balance between the generation and anneal out in either dark and light illumination. Finally, Penn State group directed by Prof.Wronski have been examining ways to prepare more stable wide band gap solar cells and developing solar cells designs appropriate for these wide gap materials. They attempted to employ the stable a-Si : H fabricated by " Chemical Annealing". In addition, Penn State group established clearly the structural relaxation induced by permeation of atomic hydrogen by their Spectroscopic Ellipsometry. The evidences obtained by these analysis offered a strong support to the "Chemical Annealing" for promotion of structural relaxation. Less