1999 Fiscal Year Annual Research Report

ワイドギャップ半導体ナノ量子ドットの構築

Research Project

Project/Area Number	10305001
Research Institution	Tohoku University
Principal Investigator	八百隆文東北大学, 金属材料研究所, 教授 (60230182)
Co-Investigator(Kenkyū-buntansha)	具本欣東北大学, 金属材料研究所, 助手 (00312645) 牧野久雄東北大学, 金属材料研究所, 助手 (40302210) 花田貴東北大学, 金属材料研究所, 助手 (80211481) グラビアローレント東北大学, 金属材料研究所, 日本学術振興会外国人特別研究員
Keywords	量子ドット / ワイドギャップ半導体 / 量子構造 / プラズマ援用MBE / ZnO / ZnSe / CdSe / GaN
Research Abstract	本年度の主要な研究成果は(1)異種基盤上でのZnO薄膜の分子層制御によるZnMgO/ZnO/ZnMgOヘテロ構造形成、(2)ZnOエピタキシ膜中での励起子分子の形成、(3)ZnSe表面上のCdSe量子ドット自己形成機構の解明である。 (1)格子不整合が18%のAl_2O_3基板上でも、MgO低温バッファー層を用いることによって、ZnOは層状成長をすることを見出した。また、格子不整3%のGaNエピ膜上では、Zn表面処理とZnO低温バッファー層を用いることで層状成長が可能になった。RHEED振動をモニターしてZnMgO/ZnO/ZnMgO量子井戸構造を形成した。光励起によって、この量子井戸構造からの誘導放出に成功した。 (2)ZnOのMBE成長においてステップフロー成長を実現させ、深い準位からの発光が全く観測されない超高品質ZnO膜の成長が可能になった。このような超高品質ZnOエピ膜を光励起すると、150w/cm^2程度で励起子分子による発光が現われ、5kw/cm^2で励起子-励起子散乱発光に推移した。 (3)前年度に実現した超平坦ZnSe表面上にCdSe量子ドットが自己形成される過程をRHEEDその場観察した。RHEEDパターンRHEEDの鏡面により反射点強度(1,0)回折点強度、平面格子定数を測定した。解析の結果、CdSe量子ドットの形成に至る表面エネルギー変化を明かにし、自己形成量子ドットのサイズ制御の指針を得ることができた。

Research Products

(16 results)

All Other

All Publications (16 results)

[Publications] O.A.Korotchenkov: ""Acoustic driving effect on radiative decays of excitons in ZnSe/ZnS single quantum wells""Appl. Phys. Lett.. 74・21. 1-3 (1999)
[Publications] J.H.Chang: ""MBE growth and characterization of (ZnMg)(SeTe)""J. Korean Phys. Soc.. 34. 4-6 (1999)
[Publications] A.Yamamoto: ""Pump-probe mearurement of ZnO epitaxial thin films""J. Korean Phys. Soc.. 34. 58-60 (1999)
[Publications] M.W.Cho: ""Molecular beam epitaxy growth of Be-chalcogenides and fabrication of ZnSe/ZnMgBeSe laser structures""J. Cryst. Growth. 201/202. 957-960 (1999)
[Publications] J.H.Chang: ""Low-threshold optically pumped lasing at 444 nm at room temperature with high characteristic temperature from Be-chalcogenide-based single-quantum-well laser structures""Appl. Phys. Lett.. 75・7. 894-896 (1999)
[Publications] E.Kurtz: ""Growth and time-resolved photoluminescence study of self-organized CdSe quantum dots in ZnSe""Superlattices and Microstructures. 25・1/2. 119-125 (1999)
[Publications] A.Yamamoto: ""Dynamics of photoexcited carriers in ZnO epitaxial thin films""Appl. Phys. Lett.. 75・4. 469-471 (1999)
[Publications] M.W.Cho: ""Non-alloyed Au/p-ZnSe/p-BeTe ohmic contact layers for ZnSe-based blue-green laser diodes""Electr. Lett.. 35・20. 1740-1742 (1999)
[Publications] D.C.Kim: ""Possibility of using BeMgZnSe as a new cladding material for ZnSe-based blue laser diodes""J. Korean Phys. Soc.. 35・4. 334-338 (1999)
[Publications] H.J.Ko: ""Two-step MBE growth of ZnO layers on electron beam exposed (111)CaF2""J. Cryst .Growth. 207. 87-94 (1999)
[Publications] K.Arai: ""Self-assembled formation of ZnCdSe quantum dots on atomically smooth ZnSe surfaces on GaAs (001) by molecular beam epitaxy""Thin Solid Films. 357. 1-7 (1999)
[Publications] D.M.Bagnall: ""Plasma assisted molecular beam epitaxy of ZnO for optoelectronic applications""Recent Res. Devel .Crystal Growth Res.. 1. 257-273 (1999)
[Publications] Y.F.Chen: ""Plasma-assisted molecular-beam epitaxy of ZnO epilayers on atomically flat MgAl2O4 (111) substrates""Appl.Phys.Lett.. 71・9. 1192-1194 (2000)
[Publications] Y.F.Chen: ""Layer-by-layer growth of ZnO epilayer on Al2O3(0001)by using a MgO buffer layer""Appl. Phys. Lett.. 76・5. 559-561 (2000)
[Publications] H.J.Ko: ""Effects of a low-temperature buffer layer on structural properties of ZnO epilayers grown on (111) CaF2 by two-step MBE""J. Cryst .Growth. 208. 389-394 (2000)
[Publications] S.K.Hong: ""Defect characterization in epitaxial ZnO/epi-GaN/Al2O3 heterostructures: transmission electron microscopy and triple-axis X-ray diffractometry""J. Cryst .Growth. 209. 537-541 (2000)

1999 Fiscal Year Annual Research Report

ワイドギャップ半導体ナノ量子ドットの構築

Principal Investigator

八百 隆文 東北大学, 金属材料研究所, 教授 (60230182)

Research Products

[Publications] O.A.Korotchenkov: ""Acoustic driving effect on radiative decays of excitons in ZnSe/ZnS single quantum wells""Appl. Phys. Lett.. 74・21. 1-3 (1999)

[Publications] J.H.Chang: ""MBE growth and characterization of (ZnMg)(SeTe)""J. Korean Phys. Soc.. 34. 4-6 (1999)

[Publications] A.Yamamoto: ""Pump-probe mearurement of ZnO epitaxial thin films""J. Korean Phys. Soc.. 34. 58-60 (1999)

[Publications] M.W.Cho: ""Molecular beam epitaxy growth of Be-chalcogenides and fabrication of ZnSe/ZnMgBeSe laser structures""J. Cryst. Growth. 201/202. 957-960 (1999)

[Publications] J.H.Chang: ""Low-threshold optically pumped lasing at 444 nm at room temperature with high characteristic temperature from Be-chalcogenide-based single-quantum-well laser structures""Appl. Phys. Lett.. 75・7. 894-896 (1999)

[Publications] E.Kurtz: ""Growth and time-resolved photoluminescence study of self-organized CdSe quantum dots in ZnSe""Superlattices and Microstructures. 25・1/2. 119-125 (1999)

[Publications] A.Yamamoto: ""Dynamics of photoexcited carriers in ZnO epitaxial thin films""Appl. Phys. Lett.. 75・4. 469-471 (1999)

[Publications] M.W.Cho: ""Non-alloyed Au/p-ZnSe/p-BeTe ohmic contact layers for ZnSe-based blue-green laser diodes""Electr. Lett.. 35・20. 1740-1742 (1999)

[Publications] D.C.Kim: ""Possibility of using BeMgZnSe as a new cladding material for ZnSe-based blue laser diodes""J. Korean Phys. Soc.. 35・4. 334-338 (1999)

[Publications] H.J.Ko: ""Two-step MBE growth of ZnO layers on electron beam exposed (111)CaF2""J. Cryst .Growth. 207. 87-94 (1999)

[Publications] K.Arai: ""Self-assembled formation of ZnCdSe quantum dots on atomically smooth ZnSe surfaces on GaAs (001) by molecular beam epitaxy""Thin Solid Films. 357. 1-7 (1999)

[Publications] D.M.Bagnall: ""Plasma assisted molecular beam epitaxy of ZnO for optoelectronic applications""Recent Res. Devel .Crystal Growth Res.. 1. 257-273 (1999)

[Publications] Y.F.Chen: ""Plasma-assisted molecular-beam epitaxy of ZnO epilayers on atomically flat MgAl2O4 (111) substrates""Appl.Phys.Lett.. 71・9. 1192-1194 (2000)

[Publications] Y.F.Chen: ""Layer-by-layer growth of ZnO epilayer on Al2O3(0001)by using a MgO buffer layer""Appl. Phys. Lett.. 76・5. 559-561 (2000)

[Publications] H.J.Ko: ""Effects of a low-temperature buffer layer on structural properties of ZnO epilayers grown on (111) CaF2 by two-step MBE""J. Cryst .Growth. 208. 389-394 (2000)

[Publications] S.K.Hong: ""Defect characterization in epitaxial ZnO/epi-GaN/Al2O3 heterostructures: transmission electron microscopy and triple-axis X-ray diffractometry""J. Cryst .Growth. 209. 537-541 (2000)

八百隆文東北大学, 金属材料研究所, 教授 (60230182)