- 著者
- Baba Masakazu Tsurekawa Sadahiro Watanabe Kentaro Du W. Toko Kaoru Hara Kosuke O. Usami Noritaka Sekiguchi Takashi Suemasu Takashi
- 出版者
- American Institute of Physics
- 雑誌
- Applied physics letters (ISSN:00036951)
- 巻号頁・発行日
- vol.103, no.14, pp.142113, 2013-09
- 被引用文献数
- 29 3
Potential variations around the grain boundaries (GBs) on the surface in undoped n-BaSi2 epitaxial films on Si(111) and Si(001) were analyzed using Kelvin prove force microcopy. The potentials were higher at GBs than those in the BaSi2 grains on Si(111). The average barrier height was approximately 30 meV at the GBs, indicating that the enhanced potentials repulse photogenerated holes so that the charge carrier recombination can be effectively reduced. In contrast, the potentials were smaller at GBs in the BaSi2 on Si(001), and the average barrier heights were approximately 30 and 50 meV along Si[1–10] and [110], respectively.
- 著者
- Tayagaki Takeshi Hoshi Yusuke Usami Noritaka
- 出版者
- Nature Publishing Group
- 雑誌
- Scientific reports (ISSN:20452322)
- 巻号頁・発行日
- vol.3, 2013
- 被引用文献数
- 64
量子ドットを用いた結晶シリコン太陽電池の高効率化に向けた設計指針を提供. 京都大学プレスリリース. 2013-09-26.
- 著者
- Khan M. Ajmal Hara Kosuke O. Nakamura Kotaro Du Weijie Baba Masakazu Toh Katsuaki Suzuno Mitsushi Toko Kaoru Usami Noritaka Suemasu Takashi
- 出版者
- Elsevier B.V.
- 雑誌
- Journal of crystal growth (ISSN:00220248)
- 巻号頁・発行日
- vol.378, pp.201-204, 2013-09
- 被引用文献数
- 18 1
We have successfully grown a-axis-oriented p-type BaSi2 films on Si(111) by in situ boron (B) doping using molecular beam epitaxy (MBE). The hole concentration in B-doped BaSi2 was controlled in the range between 1017 and 1019 cm−3 at room temperature by changing the temperature of the B Knudsen cell crucible. The acceptor level was estimated to be approximately 23 meV.
1 0 0 0 OA Temperature dependent Al-induced crystallization of amorphous Ge thin films on SiO2 substrates
- 著者
- Toko Kaoru Fukata Naoki Nakazawa Koki Kurosawa Masashi Usami Noritaka Miyao Masanobu Suemasu Takashi
- 出版者
- Elsevier B.V.
- 雑誌
- Journal of crystal growth (ISSN:00220248)
- 巻号頁・発行日
- vol.372, pp.189-192, 2013-06
- 被引用文献数
- 15 4
High-quality crystalline Ge thin films on low-cost glass substrates are desired to reduce the fabrication cost of high-efficiency tandem solar cells. We applied an Al-induced crystallization technique to amorphous-Ge films (50-nm thickness) on SiO2 glass substrates. The annealing temperature of the sample strongly influenced the grain size and the crystal orientation in the grown polycrystalline Ge layers: low annealing temperatures resulted in large grains and high (111)-orientation fractions. As a result, annealing at 325 °C provided 98% (111)-oriented grains with average diameters of 30 μm. Moreover, the grown Ge layers could be used as an epitaxial template for chemical vapor deposition. This large-grained Ge film on a SiO2 substrate appears promising for use as a Ge light-absorbing layer, as well as an epitaxial buffer layer for group III–V compound semiconductors.
- 著者
- Okada Atsushi Toko Kaoru O. Hara Kosuke Usami Noritaka Suemasu Takashi
- 出版者
- Elsevier B.V.
- 雑誌
- Journal of crystal growth (ISSN:00220248)
- 巻号頁・発行日
- vol.356, pp.65-69, 2012-10
- 被引用文献数
- 20
We have fabricated poly-Si thin films on fused silica substrates by the Al-induced crystallization (AIC) method with SiO2 insertion layers of various thicknesses (0–20 nm). The growth morphologies of poly-Si layers were dramatically changed by the SiO2 thickness, i.e., thin layers (2 nm) provided high growth rates and (100) orientations, and thick layers (10 nm) provided low growth rates and (111) orientations. These results showed that the crystal orientation of AIC-Si significantly depends on the diffusion rate of Si atoms into the Al layer.