ZnO薄膜p型掺杂的研究进展

ZnO薄膜作为一种多功能半导体材料,近年来一直受到广泛关注.然而,如何制备高质量的p型ZnO薄膜是实现其实用化的关键.概括了p型掺杂困难的原因,并指出Ⅲ-Ⅴ族元素共掺杂可能是p型掺杂的最好方法.简单回顾了ZnO薄膜p型掺杂的研究现状,并对今后的发展趋势进行了展望.     

ZnO薄膜的p型掺杂研究进展

ZnO作为重要的第三代半导体材料在光电领域具有广泛的应用前景因而引起越来越多的关注,ZnO薄膜的p型掺杂是实现ZnO基光电器件的关键,也是ZnO材料的主要研究课题.本文论述了ZnO薄膜P型转变的难点及其解决方法,概述了ZnO薄膜p型掺杂的研究现状,提出了有待进一步研究的问题.     

p型ZnO薄膜研究进展

ZnO薄膜是一种应用广泛的半导体材料.近几年来,随着对ZnO的光电性质及其在光电器件方面应用的开发研究,ZnO薄膜成为研究热点之一.制备掺杂的p型ZnO是形成同质p-n结以及实现其实际应用的重要途径.近来已在p型ZnO及其同质结发光二极管(LED s)研究方面取得了较大的进展.目前报道的p型ZnO薄膜的电阻率已降至10-3Ω.cm量级.得到了具有较好非线性伏安特性的ZnO同质p-n结和紫外发光LED.本文就其最新进展进行了综述.     

氧化锌压敏陶瓷中氧化锌晶粒极性生长现象的研究

发现了ZnO压敏陶瓷中的锥状或柱状“突起物”现象.通过能谱发现“突起物”的物质构成是ZnO,而且是ZnO晶粒生长形成的实体,并非气体在ZnO中形成的气泡.进一步论证了这种现象是ZnO极性生长造成的,并从内因和外因两个方面进行了分析.内因是ZnO的极性晶格结构和结晶形态,外因是ZnO压敏陶瓷中Bi₂O₃液相提供了极性生长得以显现的物化环境,并且通过单独添加Bi₂O₃的97mol%ZnO+3mol%Bi₂O₃配方和100mol%纯ZnO配方制备样品进行对比实验,验证了Bi₂O₃的作用.     

ZnO薄膜V族掺杂的研究进展

ZnO薄膜作为第三代半导体功能材料,高质量的p型掺杂是基于光电器件应用的关键.概述了ZnO薄膜V族元素氮、磷、砷(N、P、As)p型掺杂的研究进展,分析对比了3种元素的掺杂和p型转变特性,简单介绍了共掺杂技术,提出了有待进一步研究的问题.     

ZnO宽带隙半导体及其基本特性

ZnO半导体是宽带隙半导体领域中继GaN和SiC之后的研究热点.同时,作为一种氧化物半导体,ZnO半导体在能带结构、晶格缺陷、抗辐照特性以及电学性质等方面具有特殊性,已有的研究中还存在一些不同的认识.本工作在阐述ZnO的晶体结构和基本性质基础之上,对其能带结构和缺陷特征、电子输运以及P型掺杂等主要的半导体特性研究现状进行了较为全面综述和分析.由于ZnO半导体具有高的激子束缚能、优良的电子输运性质、强抗辐照特性以及低成本和环境友好等显著特征,它是未来半导体光电子领域极具应用潜力的新一代宽带隙半导体材料,但是到目前为止,p型掺杂技术仍然是ZnO半导体器件面临的最大挑战.     

La2/3Sr1/3MnO3/ZnO混合物薄膜的磁电阻和伏安特性研究

利用脉冲激光沉积的方法在Si（100）氧化成SiO₂的基片上制备了(La_2/3Sr_1/3MnO₃)_x/(ZnO)_1-x混合物薄膜,研究了薄膜的磁电阻和伏安特性. X射线衍射分析表明,除了衬底SiO₂的衍射峰以外,分别出现了La_2/3Sr_1/3MnO₃（101）的衍射峰和ZnO（002）的衍射峰,且它们形成了两相共存体系. 实验表明：x=0.3的混合物薄膜表现为半导体导电特性,而x=0.4的样品则出现了典型的金属绝缘相变. 所制备的样品表现出了低场磁电阻效应和非线性伏安特性. 在0.7T磁场的作用下,x=0.3的样品在温度为60K时取得的最大磁电阻值为28.8%. 通过对伏安关系拟合表明,在La_2/3Sr_1/3MnO₃和ZnO颗粒之间存在一定的耗尽层,且产生了界面缺陷态.     

ZnO薄膜p型掺杂的研究进展

ZnO薄膜作为一种多功能半导体材料，近年来一直受到广泛关注。然而，如何制备高质量的p型ZnO薄膜是实现其实用化的关键。概括了p型掺杂困难的原因，并指出Ⅲ-Ⅴ族元素共掺杂可能是p型掺杂的最好方法。简单回顾了ZnO薄膜p型掺杂的研究现状，并对今后的发展趋势进行了展望。     

纳米ZnO对纳米ZrO2(8Y)致密特性及电导率影响研究

采用纳米ZrO₂(8Y)粉和纳米ZnO粉为原料,对掺少量ZnO的ZrO₂(8Y)进行无压烧结研究.实验结果表明,掺少量的ZnO能促进ZrO₂与Y₂O₃的反应,加快四方相向立方相的转变,样品致密度和电导率显著提高.掺0.5wt％ZnO样品在1200℃煅烧2h的陶瓷致密度为94％,700℃时的电导率为9.02×10^-3cm-1·Ω^-1.     

纳米金红石型TiO2粉体的制备及其表征

纳米金红石型二氧化钛是一种重要的新型无机功能材料,其制备及其应用在当代愈来愈受到重视．本文利用ZnCO₃包覆Ti（OH）₄沉淀,500℃预焙解,使ZnCO₃转变为ZnO;Ti（OH）₄转变为H₂TiO₃．然后溶去97wt％的包覆ZnO粉体,800℃焙烧,最终制得粒径约20～60nm的金红石型二氧化钛粉体．利用TEM、XRD、ICP对粉体粒子的形貌、大小、物相及化学组成进行了分析．     

Nitrogen doped ZnO thin films prepared by photo-assisted metal-organic chemical vapor deposition

Nitrogen-doped ZnO (ZnO:N) films were prepared by photo-assisted metal-organic chemical vapor deposition technique using NH3 as N doping source. The effects of in-situ light irradiation on the properties of ZnO:N films were studied by Hall measurements, X-ray diffraction, Raman scattering, and X-ray photoelectron spectroscopy. The results show that stable p-type ZnO:N films with a hole concentration of 3.61 x 10(17) cm(-3) was successfully achieved. Moreover, introducing proper in-situ light irradiation during the growth process can not only effectively improve the crystalline quality of ZnO films, but also enhance the activity of (N)o (N occupies O site) acceptors by removing the undesirable hydrogen atoms from ZnO:N films. Both effects are benefit for the p-type conductivity formation. Our results indicate that photo-assisted MOCVD maybe an effective technology to realize device-quality p-type ZnO:N films.     

Charge carrier and spin doping in ZnO thin films

Recent efforts on doping ZnO films for charge and spin functionality are reviewed, focusing on chemical doping for charge and spin device formation. Discussion includes the behavior of phosphorus as an acceptor and magnetism in transition metal-doped ZnO. Evidence for p-type behavior in phosphorus-doped (Zn,Mg)O grown by pulsed laser deposition is presented. The magnetic properties of ZnO co-doped with Mn and Sn are also discussed.     

Deposition of Na–N dual acceptor doped p-type ZnO thin films and fabrication of p-ZnO:(Na,N)/n-ZnO:Eu homojunction

Sodium and nitrogen dual acceptor doped p-type ZnO (ZnO:(Na, N)) films have been prepared by spray pyrolysis technique at a substrate temperature of 623 K. The ZnO:(Na, N) films are grown at a fixed N doping concentration of 2 at.% and varying the nominal Na doping concentration from 0 to 8 at.%. The XRD results show that all the ZnO:(Na, N) films exhibited (0 0 2) preferential orientation. The EDX and elemental mapping analysis shows the presence and distribution of Zn, O, Na and N in the deposited films. The Hall measurement results demonstrate that the Na–N dual acceptor doped ZnO films show excellent p-type conduction. The p-type ZnO:(Na, N) films with comparatively low resistivity of 5.60 × 10⁻² Ω cm and relatively high carrier concentration of 3.15 × 10¹⁸ cm⁻³ are obtained at 6 at.%. ZnO based homojunction is fabricated by depositing n-type layer (Eu doped ZnO) grown over the p-type layer ZnO:(Na, N). The current–voltage (I–V) characteristics measured from the two-layer structure show typical rectifying characteristics of p-n junction with a low turn on voltage of about 1.69 V. The ZnO:(Na, N) films exhibit a high transmittance (about >90%) and the average reflectance is 8.9% in the visible region. PL measurement shows near-band-edge (NBE) emission and deep-level (DL) emission in the ZnO:(Na, N) thin films.     

Investigation of thin solid ZnO films prepared by sputtering

Zinc oxide (ZnO) thin films have attracted great attention in recent years due to their unique piezoelectric and piezooptic properties, making them suitable for various microelectronics and optoelectronics applications, such as surface acoustic wave devices, optical fibers, solar cells etc. ZnO is a semiconductor with a band gap of 3.3 eV and a large exciton binding energy of 60 meV. Undoped ZnO exhibits intrinsic n-type conductivity and it enables achieving high electron concentration. However, it may be doped to obtain low resistivity p-type thin films. Among group V of the periodic table, nitrogen is used as a popular p-type dopant due to its small atomic size. However, it is difficult to achieve p-type conduction in ZnO films due to the low solubility of nitrogen and its high intensity in self compensating process upon doping.Sputtering techniques enable us to form dense and homogeneous films due to the relatively high energy of the sputtered atoms. Thus we can grow high quality ZnO films with c-axis orientation, low growth temperature, high deposition rate, large area deposition, and availability in various growths ambient. In this work, the zinc oxide films were prepared using various DC sputtering methods in an atmosphere of pure argon and an atmosphere of mixed argon with nitrogen. Optical and electrical properties of the films were investigated.     

p型ZnO和ZnO同质p-n结的研究进展

ZnO基注入式发光二极管和激光器件的研究目前仍处于初级阶段．即p型ZnO和ZnOp-n结的制备与特性研究。由于ZnO薄膜中存在较强的自补偿机制，使得很难有效地施行p型元素的掺杂。本文介绍了目前国际上通用的掺杂方法．对不同方法制备的p型ZnO和ZnOp-n结的特点进行了比较分析，并讨论了目前生长高质量的突变型ZnOp-n结所面临的问题。     

Structural and electrical properties of p-type ZnO films prepared by Ultrasonic Spray Pyrolysis

Effects of atomic ratio of Zn:N:Al and solution concentration on the structural and electrical characteristic of ZnO films deposited by Ultrasonic Spray Pyrolysis using N-Al co-doping technique were investigated. Hall measurement indicated that with increasing Al doping, conductive type of ZnO thin films changed from n-type to p-type and then to n-type again. However, the solution concentration almost has no effect on the structural and electrical properties of p-type ZnO films. X-ray Photoelectron Spectroscopy indicated that the presence of Al indeed facilitates the incorporation of N through the formation of N-Al bonds in co-doped ZnO films. In addition, Photoluminescence spectra showed p-type ZnO films with a low density of native defects.     

An approach to enhanced acceptor concentration in ZnO:N films

Owing to the low doping concentration of nitrogen and strong compensation of intrinsic donors, the attainment of highly conductive p-type ZnO films remains one of the largest challenges for the application of ZnO. An approach has been proposed to increase the doping concentration of nitrogen in ZnO by exposing the ZnO:N films in the ambient of nitrogen plasma periodically in this paper. Hall measurements and photoluminescence spectroscopy indicate that this approach is effective in improving the hole concentration in ZnO films. Under the optimized conditions, a p-type ZnO film with a hole concentration of 1.68 × 10¹⁸ cm⁻³ has been achieved.     

ZnO薄膜的制备及p型掺杂研究进展

氧化锌是一种在声表面波传感器、压电器件以及太阳能电池等方面具有很好应用前景的材料。介绍了目前制备ZnO薄膜的主要方法,综述了ZnO薄膜p型掺杂的研究现状,并对ZnO薄膜的研究进行了展望。     

氧化锌薄膜场效应晶体管的制备及工艺研究

场效应晶体管是现代微电子技术的重要组成部分.为制备氧化锌薄膜晶体管,分析了氧化锌的p型、n型掺杂特性,对p型掺杂进行了实验分析和理论探讨,比较了各种制备氧化锌薄膜晶体管的工艺特点,展示了ZnO在未来电子和光电子领域的潜在应用.     

ZnO薄膜的本征缺陷、p型掺杂及其新型功能器件

ZnO是一种宽禁带半导体材料(3.37eV),具有较高的激子结合能(60meV),室温下激子仍然存在。由于其结构特点及优异的光电性能,ZnO在微电子学、光电子学、集成光学和微电子机械系统等高技术领域有着广阔的应用前景,在国内外引起极大的关注。但本征的ZnO呈n型电导,p型ZnO的获得因较强的自补偿效应,存在较大困难,限制了其应用水平。针对ZnO目前的研究、就其本征缺陷、p型掺杂以及新型功能器件等方面做一简要评述。