A Comparative Study of MOCVD Produced ZnO Films Doped with N, As, P and Sb

ABSTRACTZnO thin films are of interest for an array of applications; including: light emitters, photovoltaics, sensors and transparent contacts among others. Of particular interest is the potential to produce p-type layers from which p-n junction devices could be routinely produced. While it is fairly routine for MOCVD to produce n-type films with doping concentrations in the 10E20 cm-3 range and resistivities below 10E-3 ohm-cm; it is very difficult to produce measurable p-type ZnO. We report on our efforts with doping films p-type using N gas sources and metalorganic sources of P, As, and Sb. Films showing acceptor bands by photoluminescence have been demonstrated; however reliable electrical measurements remain difficult. Specific problems include achieving low resistance ohmic contacts, accounting for the photo-responsiveness of ZnO films and sensitivity limits in Hall measurements of low-doped and compensated materials. The presentation will review deposition parameters, produced and processed films and material characteristics.

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p-Type Field Effect Transistor and UV-Photoconductive Characteristics of Na Doped ZnMgO Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.668.681 ◽

2013 ◽

Vol 668 ◽

pp. 681-685

Author(s):

Ya Xue ◽

Hai Ping He ◽

Zhi Zhen Ye

Keyword(s):

Thin Film ◽

Thin Films ◽

Carrier Mobility ◽

Room Temperature ◽

Zno Films ◽

Electrical Measurements ◽

Acceptor Dopant ◽

Znmgo Thin Film ◽

Effect Transistor ◽

P Type

In this study, the authors have presented results for fabricated ZnO based FET and the UV-photoconductive characteristics of Na doped ZnMgO thin ﬁlms. The electrical measurements confirmed that the conductivity of the Na doped ZnMgO thin ﬁlm is p-type, and the carrier mobility was estimated to be 2.3 cm2V-1S-1. Moreover, after exposed to the 365 nm ultraviolet light, the Na doped ZnMgO thin ﬁlms still exhibited p-type behavior under gate voltage ranging from -5 to 2 V, and the Id increased a little while the carrier mobility did not change much. The photocurrent was measured under a bias of 6 V in air at room temperature. The films performed a higher current intensity after the illumination. The instantaneous rise of the photocurrent was completed when exposed to the 365 nm ultraviolet for 20 s, after switching the ultraviolet off the photocurrent decayed in a slower rate. The enhance rate of photocurrent was about 1.33 %. Conclusively, Na is a considerable acceptor dopant for making high quality p-type ZnO films, and the tiny change in the photocurrent of p-type Na doped ZnMgO thin ﬁlm made it relatively stable when fabricating LEDs and other optoelectronic devices.

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CHARACTERIZATION OF n AND p TYPE ZNO THIN FILMS DEPOSITED BY CATHODIC PULSED FILTERED VACUUM ARC SYSTEM

International Journal of Modern Physics B ◽

10.1142/s0217979209061524 ◽

2009 ◽

Vol 23 (06n07) ◽

pp. 1719-1724

Author(s):

H. KAVAK ◽

N. H. ERDOGAN ◽

K. KARA ◽

H. YANIS ◽

Z. BAZ ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Wavelength Region ◽

Zno Thin Films ◽

Vacuum Arc ◽

Zno Films ◽

Zno Thin Film ◽

Xrd Pattern ◽

Zinc Nitride ◽

P Type

The transparent, conductive n and p -type semiconducting ZnO thin films were prepared by pulsed filtered cathodic vacuum arc deposition (PFCVAD) method. The structural, optical and electrical properties of n and p -type ZnO thin films are investigated after annealing at 450°C. 197 nm thick n -type ZnO thin film was deposited with oxygen pressure of 8.5 × 10-4 Torr . XRD pattern of annealed ZnO thin film exhibits hexagonal structure with (100), (101) and (110) orientations. The crystallite size of semiconductor ZnO thin film is 18 nm, interplanar distance 0.16 nm and lattice constant c is 0.52 nm for (110) orientation. The optical transmittance spectra of n and p -type ZnO films are over 90% in the visible wavelength region with optical energy gap 3.3 eV. p -type ZnO thin films are produced by oxidation of PFCVAD deposited zinc nitride. Zinc nitride is deposited with nitrogen pressure of 8.6 × 10-4 Torr and the thickness of this film is 179 nm. The oxidation of zinc nitride thin films at 450°C results in hexagonal structures p -type ZnO thin films. XRD pattern of this film has the same (100), (101) and (110) orientations with the same crystalline structures as the directly deposited ZnO thin film. Hall measurements indicated that ZnO films were p -type and the highest carrier concentration of 1.08 × 1018 cm -3 and mobility of 93.53 cm2/Vs were obtained.

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Synthesis and properties of p-type nitrogen-doped ZnO thin films by pulsed laser ablation of a Zn-rich Zn3N2 target

Journal of Materials Research ◽

10.1557/jmr.2007.0294 ◽

2007 ◽

Vol 22 (8) ◽

pp. 2339-2344 ◽

Cited By ~ 9

Author(s):

A. Allenic ◽

W. Guo ◽

Y.B. Chen ◽

G.Y. Zhao ◽

X.Q. Pan ◽

...

Keyword(s):

Thin Films ◽

Laser Ablation ◽

Pulsed Laser ◽

Pulsed Laser Ablation ◽

Zno Thin Films ◽

Zno Films ◽

Transmission Electron ◽

Columnar Grains ◽

P Type ◽

20 Nm

Epitaxial ZnO thin films doped uniformly with nitrogen at 1020 atoms/cm3 were fabricated by pulsed laser ablation of a Zn-rich Zn3N2 target. The films grown at 300 °C and annealed at 600 °C in O2 showed p-type conductivity. Two acceptor levels at 105 and 224 meV were determined by temperature-dependent Hall and photoluminescence measurements of the p-type samples. Transmission electron microscopy studies revealed that the p-type ZnO films consist of 10–20 nm columnar grains with a high density of defects and grain boundaries that may facilitate the annihilation of native donors and the activation of acceptors during postdeposition annealing.

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Co-doping Deposition of p-type ZnO Thin Films using KrF Excimer Laser Ablation

MRS Proceedings ◽

10.1557/proc-747-v2.3 ◽

2002 ◽

Vol 747 ◽

Cited By ~ 1

Author(s):

Kenji Ebihara ◽

Tamiko Ohshima ◽

Tomoaki Ikegami ◽

Jes Asumussen ◽

Raj K. Thareja

Keyword(s):

Thin Films ◽

Zno Thin Films ◽

Zno Films ◽

Axis Orientation ◽

Excimer Laser Ablation ◽

Co Doping ◽

Doped Zno ◽

Krf Excimer Laser ◽

P Type ◽

Nitrogenous Gases

ABSTRACTWe report on the attempt to fabricate p-type ZnO thin films using various doping techniques based on the pulsed laser deposition (PLD). As an accepter, we have doped the N atom by using high purity nitric monoxide (NO) ambient gas. NO is dissociated into N and O at an energy of 6.5 eV which is lower than at N2 (9.76 eV). Moreover the dissociation reaction of NO is simpler than other nitrogenous gases such as N2O, NO2, and NH3. One of our doping techniques is co-doping of Ga and N atom by ablating ZnO:Ga target in NO gas, and another is the ablation of the metal Zn target in NO gas. Both of Ga and N co-doped ZnO films and N doped ZnO films have c-axis orientation as well as undoped ZnO films. The surfaces of these doped films are rough while the undoped ZnO thin film is very smooth and have hexagonally shaped grains. We found it possible to fabricate the p-type ZnO film by ablating the metal Zn target in NO gas.

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PROPERTIES OF GaN-DOPED ZnO THIN FILMS PREPARED BY PULSED LASER DEPOSITION

Modern Physics Letters B ◽

10.1142/s0217984910025085 ◽

2010 ◽

Vol 24 (28) ◽

pp. 2785-2791

Author(s):

J. ELANCHEZHIYAN ◽

D. W. LEE ◽

W. J. LEE ◽

B. C. SHIN

Keyword(s):

Thin Films ◽

Pulsed Laser Deposition ◽

Pulsed Laser ◽

Laser Deposition ◽

Zno Thin Films ◽

Zno Films ◽

X Ray ◽

Doped Zno ◽

P Type ◽

Type Conduction

p-type conduction in ZnO thin films has been realized by doping with GaN . Undoped and GaN -doped ZnO thin films were prepared by the pulsed laser deposition technique. All the grown films have been characterized by X-ray diffraction (XRD), atomic force microscopy (AFM) and Hall effect measurements in order to study their structural, morphological and electrical properties, respectively. The presence of dopants in the films has been confirmed by energy dispersive X-ray spectroscopy (EDS). XRD results reveal that the wurtzite structure deviates for the films with higher concentrations of GaN . Hall measurements show that the 5 and 10 at.% GaN -doped ZnO films have p-type conduction.

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Thermodynamics and Microstructure Development in the Thin Film Reaction of Aluminum on Silicon Carbide

MRS Proceedings ◽

10.1557/proc-403-489 ◽

1995 ◽

Vol 403 ◽

Cited By ~ 1

Author(s):

T. S. Hayes ◽

F. T. Ray ◽

K. P. Trumble ◽

E. P. Kvam

Keyword(s):

Thin Film ◽

Thin Films ◽

Silicon Carbide ◽

Ohmic Contacts ◽

Microstructure Development ◽

P Type ◽

Microstructural Studies

AbstractA refined thernodynamic analysis of the reaction between molen Al and SiC is presented. The calculations indicate much higher Si concentrations for saturation with respect to AkC 3 formation than previously reported. Preliminary microstructural studies confirm the formation of interfacial A14C3 for pure Al thin films on SiC reacted at 9000C. The implications of the calculations and experimental observations for the production of ohmic contacts to p-type SiC are discussed.

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Fabrication of high hole-carrier density p-type ZnO thin films by N–Al co-doping

Applied Surface Science ◽

10.1016/j.apsusc.2006.08.010 ◽

2007 ◽

Vol 253 (8) ◽

pp. 3825-3827 ◽

Cited By ~ 8

Author(s):

Zhang Xiaodan ◽

Fan Hongbing ◽

Zhao Ying ◽

Sun Jian ◽

Wei Changchun ◽

...

Keyword(s):

Thin Films ◽

Carrier Density ◽

Zno Thin Films ◽

Co Doping ◽

P Type

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Effects of the Sputtering Time of AlN Buffer Layer on the Quality of ZnO Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.881-883.1117 ◽

2014 ◽

Vol 881-883 ◽

pp. 1117-1121 ◽

Cited By ~ 1

Author(s):

Xiang Min Zhao

Keyword(s):

Thin Films ◽

Buffer Layer ◽

Rf Magnetron Sputtering ◽

Buffer Layers ◽

Zno Thin Films ◽

Zno Films ◽

Si Substrates ◽

Atomic Force ◽

Structure Morphology ◽

Aln Buffer

ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.

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