青色LED、安価な原料で実現。低コスト化へ一歩
39 ：名無しのひみつ：
Repeated temperature modulation epitaxy for p-type doping and light-emitting diode based on ZnO
ATSUSHI TSUKAZAKI, AKIRA OHTOMO, TAKEYOSHI ONUMA, MAKOTO OHTANI, TAKAYUKI MAKINO,
MASATOMO SUMIYA, KEITA OHTANI, SHIGEFUSA F. CHICHIBU, SYUNROU FUKE, YUSABUROU SEGAWA,
HIDEO OHNO, HIDEOMI KOINUMA and MASASHI KAWASAKI
doi:10.1038/nmat1284
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nmat/journal/vaop/ncurrent/abs/nmat1284.html
Since the successful demonstration of a blue light-emitting diode (LED)1,
potential materials for making short-wavelength LEDs and diode lasers have been
attracting increasing interest as the demands for display, illumination and
information storage grow2-4. Zinc oxide has substantial advantages including
large exciton binding energy, as demonstrated by efficient excitonic lasing on
optical excitation5, 6. Several groups have postulated the use of p-type ZnO
doped with nitrogen, arsenic or phosphorus7-10, and even p-n junctions11-13.
However, the choice of dopant and growth technique remains controversial and thee
reliability of p-type ZnO is still under debate14. If ZnO is ever to produce
long-lasting and robust devices, the quality of epitaxial layers has to be
improved as has been the protocol in other compound semiconductors15. Here we
report high-quality undoped films with electron mobility exceeding that in the
bulk. We have used a new technique to fabricate p-type ZnO reproducibly. Violet
electroluminescence from homostructural p-i-n junctions is demonstrated at room-
temperature.
ATSUSHI TSUKAZAKI, AKIRA OHTOMO, TAKEYOSHI ONUMA, MAKOTO OHTANI, TAKAYUKI MAKINO,
MASATOMO SUMIYA, KEITA OHTANI, SHIGEFUSA F. CHICHIBU, SYUNROU FUKE, YUSABUROU SEGAWA,
HIDEO OHNO, HIDEOMI KOINUMA and MASASHI KAWASAKI
doi:10.1038/nmat1284
http://www.nature.com/cgi-taf/DynaPage.taf?file=/nmat/journal/vaop/ncurrent/abs/nmat1284.html
Since the successful demonstration of a blue light-emitting diode (LED)1,
potential materials for making short-wavelength LEDs and diode lasers have been
attracting increasing interest as the demands for display, illumination and
information storage grow2-4. Zinc oxide has substantial advantages including
large exciton binding energy, as demonstrated by efficient excitonic lasing on
optical excitation5, 6. Several groups have postulated the use of p-type ZnO
doped with nitrogen, arsenic or phosphorus7-10, and even p-n junctions11-13.
However, the choice of dopant and growth technique remains controversial and thee
reliability of p-type ZnO is still under debate14. If ZnO is ever to produce
long-lasting and robust devices, the quality of epitaxial layers has to be
improved as has been the protocol in other compound semiconductors15. Here we
report high-quality undoped films with electron mobility exceeding that in the
bulk. We have used a new technique to fabricate p-type ZnO reproducibly. Violet
electroluminescence from homostructural p-i-n junctions is demonstrated at room-
temperature.
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