Electron Mobility in Tris（8—Hydroxyquinolinolato）Aluminum Thin Film Based on Silicium^①②

We have measured the mobilities of electrons in thin,vapor-deposited films of tris(8-hydroxyquinolinolato) aluminum(Alq 3) 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 5 V·cm -1 ,the effective mobility of electron is 1.0×10 -5 cm 2·V -1 ·s -1 for 200 nm thick sample.     

Estimation of electron mobility of n-doped 4, 7-diphenyl-1, 10-phenanthroline using space-charge-limited currents

The electron mobilities of 4, 7-diphenyl-1, 10-phenanthroline (BPhen) doped 8-hydroxyquinolinatolithium (Liq) at various thicknesses (50-300 nm) have been estimated by using space-charge-limited current measurements. It is observed that the electron mobility of 33 wt% Liq doped BPhen approaches its true value when the thickness is more than 200 nm. The electron mobility of 33 wt% Liq doped BPhen at 300 nm is found to be ～5.2 × 10~(-3) cm~2/(V·s) (at 0.3 MV/cm) with weak dependence on electric field, which is about one order of magnitude higher than that of pristine BPhen (3.4 × 10~(-4) cm~2/(V·s)) measured by SCLC. For the typical thickness of organic light-emitting devices, the electron mobility of doped BPhen is also investigated.     

基于溶液法的金属诱导碟型晶畴多晶硅薄膜和薄膜晶体管的研究

以非晶硅为晶化前驱物,采用镍盐溶液浸沾的方法可以得到超大尺寸碟型晶畴结构的低温多晶硅薄膜.所得多晶硅薄膜的平均晶畴尺寸大约为50 μm,空穴的最高霍尔迁移率为30.8 cm~2/V·s,电子的最高霍尔迁移率为45.6 cm~2/V·s.用这种多晶硅薄膜为有源层,所得多晶硅TFT的场效应迁移率典型值为70～80 cm~2 /V·s,亚阈值斜摆幅为1.5 V/decade,开关电流比为1.01×10~7,开启电压为-8.3 V.另外,P型的TFT在高栅偏压和热载流子偏压下具有良好的器件稳定性.     

MAPbI3单晶光电探测器的制备及应用

采用逆温法生长得到了MAPbI3单晶,经过粗磨抛光处理后,作为靶材在其表面蒸镀了Au电极,制备了Au/MAPbI3/Au光电探测器,并对其光电性能进行了详细研究。在不同光照条件下的I-V性能测试结果表明,相同的偏压下MAPbI3单晶光电探测器均具有较好的光敏感性和探测性能。通过α能谱和飞行时间(TOF)技术研究并讨论了该探测器对α粒子的探测性能,并最终得到探测器中电子和空穴的电子迁移率和寿命乘积分别为5.6×10^-4和3.3×10^-4 cm^2/V,电子和空穴的迁移率分别为24.6和59.7 cm^2/(V·s)。实验结果表明,该探测器的探测能力与室温核辐射探测材料CdZnTe的相当,证实了逆温法生长的MAPbI3单晶具有优异的电荷传输性能,在室温辐射检测领域有巨大的潜力。     

退火温度对SnF2掺杂SnO2薄膜性能的影响

利用电子束蒸镀技术在石英玻璃上沉积SnF2掺杂SnO2(FTO)薄膜.研究了不同退火温度对FTO薄膜结构和光电性能的影响.研究结果表明:升高退火温度可促进FTO薄膜中晶粒逐渐变大,结晶度变好,同时薄膜在可见光范围内的透射率随着退火温度升高逐渐增加,吸收边发生蓝移,禁带宽度显著变宽,这是由于载流子浓度增加导致的Moss-Burstein效应.升高温度时,薄膜电学性能随着退火温度升高有了很大改善,700℃退火处理后得到电阻率低至2.74×101 Ω·cm、载流子浓度为2.09×1020 cm-3、迁移率为9.93 cm2·V 1·s 1的FTO薄膜.     

Field dependence of mobility in Al0.2Ga0.8As/GaAs heterojunctions at very low fields

Multiple-period (Al, Ga)As/GaAs modulation doped heterojunction structures have been grown with molecular beam epitaxy. Electron mobilities of about 200 000 cm2/Vs at 10 K and 90000 cm2/Vs at 77 K with associated sheet carrier concentrations of about 2×1012 cm?2 have been observed. The current parallel to the interfaces for low electric fields was examined as a function of lattice temperature. The electron mobility has been observed to be strongly dependent on the strength of the electric field, and hot electron effects were observable at a field as low as 10 V/cm. To our knowledge this is the first report of hot electron phenomena in GaAs at such small fields.     

MOCVD生长AlGaN/GaN/Si(111)异质结材料

利用MOCVD在Si(111)衬底上生长了无裂纹的GaN外延薄膜和AlGaN/GaN异质结构。通过优化Si衬底的浸润处理时间、AlN层厚度等参数获得了无裂纹的GaN外延薄膜,研究了SiN缓冲层和插入层厚度对AlGaN/GaN异质结电学性质的影响,2DEG的迁移率和面密度分别达到1410cm2/V.s和1.16×1013cm-2。     

Drift mobility of carriers in porous silicon

The drift mobility of carriers in porous silicon has been studied in a wide temperature range (190–360 K) at electric field strengths of 2×10³–3×10⁴ V/cm. An exponential temperature dependence of the hole drift mobility with an activation energy of d ～ 0.14 eV was established. The density of localized states controlling the transport is evaluated.     

MOCVD生长的SiC衬底高迁移率GaN沟道层AlGaN/AlN/GaN HEMT结构

用MOCVD技术在高阻6H-SiC衬底上研制出了具有高迁移率GaN沟道层的AlGaN/AlN/GaN高电子迁移率晶体管(HEMT)结构材料,其室温和80K时二维电子气迁移率分别为1944和11588cm2/(V·s),相应二维电子气浓度为1.03×1013cm-2;三晶X射线衍射和原子力显微镜分析表明该材料具有良好的晶体质量和表面形貌,10μm×10μm样品的表面粗糙度为0.27nm.用此材料研制出了栅长为0.8μm,栅宽为1.2mm的HEMT器件,最大漏极饱和电流密度和非本征跨导分别为957mA/mm和267mS/mm.     

Low voltage copper phthalocyanine organic thin film transistors with a polymer layer as the gate insulator

Low voltage organic thin film transistors(OTFTs) were created using polymethyl-methacrylate-co g-lyciclyl-methacrylate(PMMA-GMA) as the gate dielectric.The OTFTs performed acceptably at supply voltages of about 10 V.From a densely packed copolymer brush,a leakage current as low as 2×10~(-8) A/cm~2 was obtained.From the measured capacitance-insulator frequency characteristics,a dielectric constant in the range 3.9-5.0 was obtained. By controlling the thickness of the gate dielectric,the threshold voltage ...