C) 13K, gin bd viing cam xuat hien hai vach hep vdi cudng do manh d 456nm va 461nm n i m trdn nen cua dam phat quang mau xanh lam tir
SI; PHAT QUANG CUA TINH THE Zne Pham Van B§n , Bui Hong Van
Pham Van B§n , Bui Hong Van
Khoa Vat ly ,Trudng Dai hoc Khoa hgc Tu nhien, Dai hgc Quoc gia Ha Ndi 334 Nguyen Trai, Thanh Xuan , Ha Ndi
Phd phat quang ciia tinh the ZnSe dl3K dugc kich thich bing cac budc sdng 365nm va 450nm cua den Xenon chi xuit hien nhirng vach^va nhiing dam phat quang d viing xanh lam tir 450nm đn 500nm va xanh la cay vdi cue dai d 570nm. Cac vach va cac dam nay dac trung cho tai hgp bue xa cua exciton lien ket tren cac nut khuydt cua Zn (Vzn) vdi su tham gia ciia cac phonon quang LO, cac cap donor-acceptor ndng va tap chit. Khi tang nhiet do, cudng do cua cac vach va cac dam đu giam. Ci 300K, khi tinh the ZnSe dugc kich thich bang budc sdng 488nm cua laser Argon vdi mat do nang lugng kich thich tir 4.2w/cm^ đn 33.7 \v/cm^, trong phd phat quang xuit hien mdt dam rdng d viing da cam - đ vdi cue dai dich chu\'§n v6 phia nang lugng Idn (khoang 11 meV). Dam nay dac trung cho tai hgp birc xa ciia nhirng cap donor ndng va acceptor sau d gan nhau .
Ị MO DAU
Phd phat quang cua tinh the ZnSe d viing xanh lam tir 13K đn 300K da dugc nghien cim nhieụ O viing phd nay, ngoai cac vach dac trung cho su tai hgp birc xa ciia cac exiton tu do, exciton Hen ket tren cac donor, acceptor cdn xuat hien cac dam rdng dac trung cho tai hgp bue xa cua cac cap donor-acceptor ndng [1.2.3.4]. Tuy nhien. phd phat quang ciia tinh the ZnSe d vimg xanh la cay va viing da cam - đ dugc nghien cim it \ a ban chat birc xa ciia cac dam nay dugc giai thich kliac nhau [2,4]. Nham lam sang td mdt \'ai ca che tai hgp biic xa va kha nang img dung ciia tinh the ZnSe trong cac N'iing phd nay, chiing tdi da tien hanh nghien ciru phd phat quang ciia tinh the ZnSe tir 13K den 300K vdi nhirng mat do nang lugng kich thich khac nhau .
IL MAU NGHIEN ClTU VA THIET BI THlTC NGHIEM
Tinli the ZnSe dugc nudi bang phuang phap ndng chay vimg do Vien Han Lam YOOE chi taọ Phd phat quang ciia nd tir 13K den 300K dugc kich thich bing doi Xenon XFOR-450 , laser Argon 237A va dugc ghi tren cac phd ke FL3-22. GDM -1000 vdi khudch dai lock-in SR830 ( D - 5 A % i m ) .
IIỊ KET QUA VA BIEN LUAN l.Pho phat quang cua tinh the ZnSe l.Pho phat quang cua tinh the ZnSe
Hinhlạ lb la phd phat quang ciia tinh the ZnSe tii" 13K den 300K khi kich thich bing cac budc sdng 365nm va 450nm ciia den Xenon
Bdo cao tai Hoi nghi Vat ly toan quoc Idn thu VI, Hd Npi 23 -25/11/2005 1200000 450 500 550 600 650 700 Wavelength (nm) 450 500 550 600 650 700 Wavelength (nm)
Hinh la, lb : Pho phdt quang cua tinh the ZnSe khi kich thich bdng buac song 365nm vd 450nm cua den Xenon tic 13Kdin 300K