CN102290707A

CN102290707A - Ultraviolet-visible coexisting electrically pumped random laser device and preparation method thereof

Info

Publication number: CN102290707A
Application number: CN2011101945851A
Authority: CN
Inventors: 马向阳; 田野; 杨德仁
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2011-07-12
Filing date: 2011-07-12
Publication date: 2011-12-21
Anticipated expiration: 2031-07-12
Also published as: CN102290707B

Abstract

The invention discloses an ultraviolet-visible coexisting electrically pumped random laser device and a preparation method thereof. The device comprises a substrate, a first SiO2 membrane, a CdO membrane, a ZnO membrane, a second SiO2 membrane and an Au electrode are deposited on the front of the substrate sequentially from the bottom up, and an ohm contact electrode is deposited on the back of the substrate. A SiO2/ZnO/CdO/SiO2 double-barrier structure is formed on the substrate of the device, the ZnO membrane layer and the CdO membrane layer are formed into a Cdx Zn1 minus x O membrane luminous layer because of the mutual diffusion of cadmium and zinc, the Cd concentration of the Cdx Zn1 minus x O membrane luminous layer is gradually changed, and under a certain forward bias (the substrate is connected with negative voltage), the CdZnO membrane can emit electrically pumped random laser positioned in ultraviolet and visible regions. Moreover, the structure and implementation method of the device are simple, and the preparation technique and the used equipment are compatible with the conventional mature silicon device technique.

Description

Ultraviolet and electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare and preparation method visible and that deposit

Technical field

The present invention relates to a kind of electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare, be specially a kind of based on SiO on the silicon substrate ₂/ ZnO/CdO/SiO ₂The ultraviolet of dual potential barrier structure and electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare and preparation method visible and that deposit.

Background technology

Because the development of photoelectric technology to the demand of ultraviolet, visual field Laser Devices and other short-wavelength light electric devices, makes the Random Laser research of ZnO receive increasing concern.As the important a member in the ZnO system, the CdZnO film is by regulating the content of Cd, can be effectively the emission wavelength of CdZnO film be adjusted to visible region.(J.A.Van?Vechten?and?T.K.Bergstresser，Phys.Rev.B.1，3351(1970))。Penetrate luminously if can utilize the CdZnO film to be implemented in swashing at random of visual field, to have active operation significance undoubtedly.

2006, people's reported first such as H.D.Li ultraviolet, the optical pumping visible and ZnO film deposited swash at random and penetrate (H.D.Li, S.F.Yu, S.P.Lau, and E.S.Leong, Appl.Phys.Lett.89,021110 (2006)).Yet swash for ZnO film and CdZnO film electric pumping random and to penetrate, at present report not also in the visual field.Its main bottleneck is the solid solubility of CdO in the CdO-ZnO alloy system very low (approximately having only 2mol% under thermal equilibrium state) on the one hand, so be difficult to utilize simple equipment to prepare the CdZnO film of high Cd content.The molten boiling point that Cd is lower makes that again preparation becomes very difficult based on the CdZnO membrane electro luminescent device of high Cd doped in concentrations profiled on the other hand.

Horse waited the people to utilize metal-insulator layer-semiconductor (MIS) structure on the sunny side in 2007, successfully realized sharp (the Xiangyang Ma that penetrates of electric pumping random of ZnO film, Peiliang Chen, DongshengLi, Yuanyuan Zhang, and Deren Yang, Appl.Phys.Lett.90,231106 (2007)).Recently again by changing Mg _xZn _1-XThe component of O film utilizes this MIS structure to realize continuously adjustable (Ye Tian, Xiangyang Ma, Peiliang Chen, Yuanyuan Zhang, Deren Yang, Opt.Express.18,10668 (2010)) of optical maser wavelength in the ultra-violet (UV) band.How can study on the basis at this, to realize that the electric pumping random of CdZnO film in the visual field swashs to penetrate luminously, be a difficult problem needing solution badly.

Summary of the invention

The invention provides a kind of ultraviolet and electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare visible and that deposit, realized the electric pumping random of CdZnO film in the visual field swash penetrate luminous.

A kind of ultraviolet and electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare visible and that deposit comprise substrate, and substrate face deposits a SiO from bottom to top successively ₂Film, CdO film, ZnO film, the 2nd SiO ₂Film and Au electrode, substrate back deposition Ohm contact electrode.

Described substrate is that resistivity is the N type silicon chip of 0.005～50 ohmcm.

The thickness of CdO film helps bright dipping greater than the thickness of ZnO film.

The present invention also provides the preparation method of above-mentioned electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare, comprising:

(1) adopt sol-gel process on substrate, to deposit a SiO ₂Film;

(2) adopt sputtering method at a SiO ₂Deposition CdO film on the film;

(3) adopt sputtering method on the CdO film, to deposit ZnO film, heat treated;

(4) adopt sol-gel process to deposit the 2nd SiO at ZnO film ₂Film;

(5) adopt sputtering method at the 2nd SiO ₂The translucent Au electrode of deposition on the film is at substrate back deposition Ohm contact electrode.

Preferably, deposition SiO in step (2) and the step (4) ₂Carry out heat treated behind the film, 400～500 ℃ of heating-up temperatures can be removed the organic substance in the film 1～2 hour heating time, help film forming.

Carry out heat treated behind the deposition ZnO film in the step (3), can make Cd, Zn produce enough counterdiffusion, and adopt higher heat treatment temperature can make the thin-film light emitting grow, but temperature can not be too high, because Cd is easy to volatilization and phase-splitting at high temperature, preferred 600～800 ℃ of heating-up temperature, 1～5 hour heating time.

Device of the present invention has formed SiO on substrate ₂/ ZnO/CdO/SiO ₂Dual potential barrier structure, because the counterdiffusion of cadmium, zinc, ZnO/CdO two thin layers have constituted the Cd of Cd concentration gradient _xZn _1-xO thin-film light emitting layer, under certain forward bias (substrate connects negative voltage), the CdZnO film can send the electric pumping random that is positioned at ultraviolet, visual field and swash and to penetrate.And the structure of device and implementation are simple, preparation technology and used equipment and the silicon device process compatible of existing maturation.

Description of drawings

Fig. 1 is the structural representation of device of the present invention;

Fig. 2 is the ZnO/CdO/SiO of the embodiment of the invention 1 ₂Film is through the secondary ion mass spectroscopy (SIMS) after the high-temperature heat treatment;

Fig. 3 is electroluminescence (EL) spectrum that the electroluminescent device of the embodiment of the invention 1 obtains under different forward currents;

Fig. 4 is electroluminescence (EL) spectrum that the electroluminescent device of the embodiment of the invention 2 obtains under different forward currents.

Embodiment

As Fig. 1, a kind of electricity is sent a telegraph pumping Amplifier Based On Stimulated Emission Of Radiation spare at random, comprises substrate 1, and substrate 1 front deposits SiO from bottom to top successively ₂ Film 2, CdO film 3, ZnO film 4, SiO ₂ Film 5 and translucent Au electrode 6, substrate 1 backside deposition has Ohm contact electrode 7.Substrate is selected silicon chip for use, and resistivity is generally 0.005～50 ohmcm.Embodiment 1 and embodiment 2 have prepared the device of said structure, and be specific as follows:

Embodiment 1

1) clean N type＜100 〉, resistivity is that 0.005 ohmcm, size are 15 * 15mm ², thickness is 675 microns silicon chip;

2) utilize tetraethoxysilane, alcohol, watery hydrochloric acid prepare SiO by a certain percentage ₂Colloidal sol.Spin coating one deck SiO on silicon chip ₂Film was dried 10 minutes for 100 ℃, at O ₂The following 500 ℃ of heat treatments of atmosphere 2 hours;

3) utilize radio frequency sputtering at SiO ₂Deposition CdO film on the film, underlayer temperature is 300 ℃;

Sputtering power is 120W, Ar, O ₂Flow be respectively air pressure 4Pa, sputter 1 hour, the about 400nm of thickness 30: 15.

4) utilize radio frequency sputtering to deposit ZnO film on the CdO film, underlayer temperature is 150 ℃, and sputtering power is 100W, Ar, O ₂Flow be respectively air pressure 3Pa 30: 15.Sputter 10 minutes, the about 40nm of thickness; The deposition back is at O ₂The following 750 ℃ of heat treatments of atmosphere 1 hour;

5) spin coating one deck SiO on ZnO film ₂Film, 100 ℃ of oven dry 10 minutes, 500 ℃ of heat treatment is 2 hours under air;

6) at SiO ₂The thick translucent Au electrode of the about 20nm of sputter on the film, and the Au electrode that the about 100nm of sputter is thick on the silicon substrate back side (Ohm contact electrode 7).Sputtering power is 45W, and the Ar flow is 20, and air pressure 5Pa, underlayer temperature are 150 ℃.Front electrode sputter 30 seconds, backplate sputter 3 minutes.

Fig. 2 has provided the ZnO/CdO/SiO by method for preparing ₂The secondary ion mass spectroscopy of film (SIMS).Two kinds of elements of Cd, Zn have formed counterdiffusion through after the high-temperature heat treatment as we can see from the figure.Begin increase along with the degree of depth from topsheet surface, the content of Zn reduces gradually, and the content of Cd increases gradually, and this has also proved the Cd that has constituted the Cd concentration gradient at ZnO/CdO two thin layers _xZn _1-xO thin-film light emitting layer.

Fig. 3 has provided different injection currents electroluminescence (EL) spectrum down that the device that obtains by said method at room temperature records, top layer Si O at this moment ₂Au electrode on the film just connects, and the Au electrode of Si substrate back connects negative.As we can see from the figure, device is at ultraviolet region, and sharp-pointed glow peak has all appearred in the ruddiness zone, and along with the increase of injection current, electroluminescent intensity also increases thereupon.This explanation device has produced in ultraviolet, visual field to swash at random simultaneously to be penetrated.

Embodiment 2

1) clean N type＜100 〉, resistivity is that 0.005 ohmcm, size are 1515mm ², thickness is 675 microns silicon chip;

2) utilize tetraethoxysilane, alcohol, watery hydrochloric acid prepare SiO2 colloidal sol by a certain percentage.Spin coating one deck SiO on silicon chip ₂Film was dried 10 minutes for 100 ℃, at O ₂The following 500 ℃ of heat treatments of atmosphere 2 hours;

3) utilize radio frequency sputtering at SiO ₂Deposition CdO film on the film, underlayer temperature is 300 ℃; Sputtering power is 120W, Ar, O ₂Flow be respectively air pressure 4Pa 30: 15.Sputter 1 hour, the about 400nm of thickness;

4) utilize radio frequency sputtering to deposit ZnO film on the CdO film, underlayer temperature is 150 ℃, and sputtering power is 100W, Ar, O ₂Flow be respectively air pressure 3Pa 30: 15.Sputter 10 minutes, the about 100nm of thickness.At O ₂The following 750 ℃ of heat treatments of atmosphere 1 hour;

Fig. 4 has provided different injection currents electroluminescence (EL) spectrum down that the device that obtains by said method at room temperature records, top layer Si O at this moment ₂Au electrode on the film just connects, and the Au electrode of Si substrate back connects negative.As we can see from the figure, device is at ultraviolet region, and sharp-pointed glow peak has all appearred in the ruddiness zone, and along with the increase of injection current, electroluminescent intensity also increases thereupon.This explanation device has produced in ultraviolet, visual field to swash at random simultaneously to be penetrated.

Claims

1. an electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare comprises substrate, it is characterized in that, described substrate face deposits a SiO from bottom to top successively ₂Film, CdO film, ZnO film, the 2nd SiO ₂Film and Au electrode, substrate back deposits Ohm contact electrode.

2. electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare according to claim 1 is characterized in that, described substrate is that resistivity is the N type silicon chip of 0.005～50 ohmcm.

3. electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare according to claim 1 is characterized in that the thickness of described CdO film is greater than the thickness of ZnO film.

4. the preparation method of an electric pumping random Amplifier Based On Stimulated Emission Of Radiation spare comprises:

(1) adopt sol-gel process on substrate, to deposit a SiO ₂Film;

(2) adopt sputtering method at a SiO ₂Deposition CdO film on the film;

(3) adopt sputtering method on the CdO film, to deposit ZnO film, heat treated;

(4) adopt sol-gel process to deposit the 2nd SiO at ZnO film ₂Film;

5. preparation method according to claim 4 is characterized in that, deposition SiO in step (2) and the step (4) ₂Carry out heat treated behind the film, 400～500 ℃ of heating-up temperatures, 1～2 hour heating time.

6. preparation method according to claim 4 is characterized in that, the heat treated temperature is 600～800 ℃ in the step (3), and the time is 1～5 hour.