The characteristics of low frequency electrical noise, voltage current ( V I ) and electrical derivation for 980 nm InGaAsP/InGaAs/GaAs high power double quantum well lasers(DQWLs) are measured under different conditi...The characteristics of low frequency electrical noise, voltage current ( V I ) and electrical derivation for 980 nm InGaAsP/InGaAs/GaAs high power double quantum well lasers(DQWLs) are measured under different conditions. The correlation of the low frequency electrical noise with surface non radiative current of devices is discussed. The results indicate the low frequency electrical noise of 980 nm DQWLs with high power is mainly 1/ f noise and has good relation with the device surface current at low injection.展开更多
An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is introduced. SiGe alloys and SiGe/Si multiple quantum wells (MQWs) have been grown by cold-wall UHV/CVD using disilane (Si 2H 6) and germane (GeH 4) as ...An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is introduced. SiGe alloys and SiGe/Si multiple quantum wells (MQWs) have been grown by cold-wall UHV/CVD using disilane (Si 2H 6) and germane (GeH 4) as the reactant gases on Si (100) substrates. The growth rate and Ge contents in SiGe alloys are studied at different temperature and different gas flow. The growth rate of SiGe alloy is decreased with the increase of GeH 4 flow at high temperature. X-ray diffraction measurement shows that SiGe/Si MQWs have good crystallinity, sharp interface and uniformity. No dislocation is found in the observation of transmission electron microscopy (TEM) of SiGe/Si MQWs. The average deviation of the thickness and the fraction of Ge in single SiGe alloy sample are 3.31% and 2.01%, respectively.展开更多
Organic multiple quantum wells(OMQWs) consisting of alternating layers of organic materials have been fabricated from tris(8-hydroxyquinoline) aluminum(Alq)and 2-(4-biphenylyl)-5-(4-tertbutylphenyl)-1,3,3-oxadiazole(P...Organic multiple quantum wells(OMQWs) consisting of alternating layers of organic materials have been fabricated from tris(8-hydroxyquinoline) aluminum(Alq)and 2-(4-biphenylyl)-5-(4-tertbutylphenyl)-1,3,3-oxadiazole(PBD) by a multisource-type high-vacuum organic molecular deposition.From the small-angle X-ray diffraction patterns of Alq/PBD OMQWs,a periodically layered structure is confirmed through the entire stack.The Alq layer thickness in the OMQWs was varied from 1 nm to 4 nm.From the optical absorption,photoluminescence and electroluminescence measurements,it is found that the exciton energy shifts to higher energy with decreasing Alq layer thickness,The changes of the exciton energy could be interpreted as the confinement effects of exciton in the Alq thin layers.Narrowing of the emission spectrum has also been observed for the electroluminescent devices (ELDs) with the OMQWs structure at room temperature.展开更多
The mobilities of holes in thin,spin-casting films of poly( N -vinylcarbazole)(PVK) based on silicium are measured using a time-of-flight (TOF) technique.The drift of hole mobility is strongly dependent on the elect...The mobilities of holes in thin,spin-casting films of poly( N -vinylcarbazole)(PVK) based on silicium are measured using a time-of-flight (TOF) technique.The drift of hole mobility is strongly dependent on the electric field and temperature.At room temperature and an electric field of 2×10 5 V·cm -1 ,the effective mobility of hole is 7.14×10 -6 cm 2·V -1 ·s -1 ,in a 200 nm thick sample.展开更多
We have measured the mobilities of electrons in thin,vapor-deposited films of tris(8-hydroxyquinolinolato)aluminum(Alq3)based on silicium using a time-of-flight(TOF)technique.The drift of electron mobility is strongly...We have measured the mobilities of electrons in thin,vapor-deposited films of tris(8-hydroxyquinolinolato)aluminum(Alq3)based on silicium using a time-of-flight(TOF)technique.The drift of electron mobility is strongly electric field and temperature dependent.At room temperature and an electric field of 2×10^5V·cm^-1,the effective mobility of electron is 1.0×10^-5cm^2·V^-1·s^-1 for 200nm thick sample.展开更多
文摘The characteristics of low frequency electrical noise, voltage current ( V I ) and electrical derivation for 980 nm InGaAsP/InGaAs/GaAs high power double quantum well lasers(DQWLs) are measured under different conditions. The correlation of the low frequency electrical noise with surface non radiative current of devices is discussed. The results indicate the low frequency electrical noise of 980 nm DQWLs with high power is mainly 1/ f noise and has good relation with the device surface current at low injection.
基金ChineseHigh -TechnologyResearchPlan (No .863- 30 7- 15- 4 ( 0 3) )andChineseNaturalScienceFund (No .698962 60 )
文摘An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is introduced. SiGe alloys and SiGe/Si multiple quantum wells (MQWs) have been grown by cold-wall UHV/CVD using disilane (Si 2H 6) and germane (GeH 4) as the reactant gases on Si (100) substrates. The growth rate and Ge contents in SiGe alloys are studied at different temperature and different gas flow. The growth rate of SiGe alloy is decreased with the increase of GeH 4 flow at high temperature. X-ray diffraction measurement shows that SiGe/Si MQWs have good crystallinity, sharp interface and uniformity. No dislocation is found in the observation of transmission electron microscopy (TEM) of SiGe/Si MQWs. The average deviation of the thickness and the fraction of Ge in single SiGe alloy sample are 3.31% and 2.01%, respectively.
文摘Organic multiple quantum wells(OMQWs) consisting of alternating layers of organic materials have been fabricated from tris(8-hydroxyquinoline) aluminum(Alq)and 2-(4-biphenylyl)-5-(4-tertbutylphenyl)-1,3,3-oxadiazole(PBD) by a multisource-type high-vacuum organic molecular deposition.From the small-angle X-ray diffraction patterns of Alq/PBD OMQWs,a periodically layered structure is confirmed through the entire stack.The Alq layer thickness in the OMQWs was varied from 1 nm to 4 nm.From the optical absorption,photoluminescence and electroluminescence measurements,it is found that the exciton energy shifts to higher energy with decreasing Alq layer thickness,The changes of the exciton energy could be interpreted as the confinement effects of exciton in the Alq thin layers.Narrowing of the emission spectrum has also been observed for the electroluminescent devices (ELDs) with the OMQWs structure at room temperature.
文摘The mobilities of holes in thin,spin-casting films of poly( N -vinylcarbazole)(PVK) based on silicium are measured using a time-of-flight (TOF) technique.The drift of hole mobility is strongly dependent on the electric field and temperature.At room temperature and an electric field of 2×10 5 V·cm -1 ,the effective mobility of hole is 7.14×10 -6 cm 2·V -1 ·s -1 ,in a 200 nm thick sample.
文摘We have measured the mobilities of electrons in thin,vapor-deposited films of tris(8-hydroxyquinolinolato)aluminum(Alq3)based on silicium using a time-of-flight(TOF)technique.The drift of electron mobility is strongly electric field and temperature dependent.At room temperature and an electric field of 2×10^5V·cm^-1,the effective mobility of electron is 1.0×10^-5cm^2·V^-1·s^-1 for 200nm thick sample.
