• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.27-29
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• 2005

ZnO and phosphorus doped ZnO thin films (ZnO:P) are deposited by pulsed laser deposition grown on (001) $Al_{2}O_{3}$. ZnO/ZnO:P/ZnO/$Al_{2}O_{3}$ (multi-layer) structure was used for phosphorus doped ZnO fabrication. This multi-layer structure thin film was annealed at $400^{\circ}C$ for 40 min. The electron concentration of that was changed from $10^{19}$ to $10^{16}/cm^{-3}$ after annealing. ZnO thin films with encapsulated structure showed the enhanced structural and optical properties than phosphorus doped ZnO without encapsulated layer. In this study, encapsulated ZnO structure was suggested to enhance electrical, structural and optical properties of phosphorus doped ZnO thin film and it was identified that encapsulated structure could be used to fabricate high quality phosphorus doped ZnO thin film.

• Korean Journal of Materials Research
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• v.19 no.8
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• pp.417-420
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• 2009

This study develops a highly transparent ohmic contact using phosphorus doped ZnO with current spreading for p-GaN to increase the optical output power of nitride-based light-emitting diodes (LEDs). The phosphorus doped ZnO transparent ohmic contact layer was prepared by radio frequency magnetron sputtering with post-deposition annealing. The transmittance of the phosphorus doped ZnO exceeds 90% in the region of 440 nm to 500 nm. The specific contact resistance of the phosphorus doped ZnO on p-GaN was determined to be $7.82{\times}10^{-3}{\Omega}{\cdot}cm^2$ after annealing at $700^{\circ}C$. GaN LED chips with dimensions of $300\times300{\mu}m$ fabricated with the phosphorus doped ZnO transparent ohmic contact were developed and produced a 2.7 V increase in forward voltage under a nominal forward current of 20 mA compared to GaN LED with Ni/Au Ohmic contact. However, the output power increased by 25% at the injection current of 20 mA compared to GaN LED with the Ni/Au contact scheme.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.55-56
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• 2005

The properties of phosphorus doped ZnO thin films deposited on (001) sapphire substrates by pulsed laser deposition (PLD) were investigated depending on various deposition conditions. The phosphorus (P) doped ZnO target was composed of ZnO + x wt% Al (x=1, 3, 5). The structural, electrical and optical properties of the ZnO thin films were measured by X-ray diffraction (XRD), Hall measurements and photoluminescence (PL). As the deposition temperature optimized, the electrical properties of the phosphorus doped ZnO (ZnO:P) layer showed a electron concentration of $7.76\times10^{16}/cm^3$, a mobility of 10.225 $cm^2/Vs$, a resistivity of 7.932 $\Omega$cm. It was observed the electrical property of the film was changed by dopant activation effect as target variations and deposition conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.51-52
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• 2005

Phosphorus doped ZnO thin films on (001) $Al_2O_3$ substrate have been prepared by a pulsed laser deposition (PLD) technique using a Nd:YAG laser. After deposition, phosphorus doped ZnO thin films have been annealed in vacuum, air, nitrogen, and oxygen ambients using pulsed Nd:YAG laser. We report the electrical properties of phosphorus doped ZnO thin films with the variation of the laser annealing conditions for the applications of optoelectronic devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05a
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• pp.127-130
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• 2005

The properties of phosphorus doped ZnO multilayer thin films deposited on (001) sapphire substrates by pulsed laser deposition (PLD) were investigated by using annealing treatment at various annealing temperature after deposition. The phosphorus doped ZnO multilayer was composed of phosphorus doped ZnO layer and two pure ZnO layers on sapphire substrate. The structural. electrical and optical properties of the ZnOthin films were measured by X-ray diffraction (XRD). Hall measurements and photoluminescence (PL). As the annealing temperature optimized. the electrical properties of the ZnO multilayer showed a electron concentration of $1.56{\times}10^{16}/cm^3$, a resistivity of 17.97 ${\Omega}cm$. It was observed the electrical property of the film was changed by dopant activation effect as thermal annealing process

• Korean Journal of Materials Research
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• v.23 no.5
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• pp.255-259
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• 2013

An effect of thermal annealing on activating phosphorus (P) atoms in ZnO nanorods (NR) grown using a hydrothermal process was investigated. $NH_4H_2PO_4$ used as a dopant source reacted with $Zn^{2+}$ ions and $Zn_3(PO_4)_2$ sediment was produced in the solution. The fact that most of the input P elements are concentrated in the $Zn_3(PO_4)_2$ sediment was confirmed using an energy dispersive spectrometer (EDS). After the hydrothermal process, ZnO NRs were synthesized and their PL peaks were exhibited at 405 and 500 nm because P atoms diffused to the ZnO crystal from the $Zn_3(PO_4)_2$ particles. The solubility of the $Zn_3(PO_4)_2$ initially formed sediment varied with the concentration of $NH_4OH$. Before annealing, both the structural and the optical properties of the P-doped ZnO NR were changed by the variation of P doping concentration, which affected the ZnO lattice parameters. At low doping concentration of phosphorus in ZnO crystal, it was determined that a phosphorus atom substituted for a Zn site and interacted with two $V_{Zn}$, resulting in a $P_{Zn}-2V_{Zn}$ complex, which is responsible for p-type conduction. After annealing, a shift of the PL peak was found to have occurred due to the unstable P doping state at high concentration of P, whereas at low concentration there was little shift of PL peak due to the stable P doping state.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.540-542
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• 2009

Phosphorus doped ZnO (PZO) thin films were deposited on $SiO_2$/n-Si substrates using DC magnetron sputtering system varying oxygen partial pressures from 0 to 40 % under Ar atmosphere. The deposited films showed reduced n-type conductivity due to the compensating donor effects by phosphorus dopant. The bias-time stability shows relatively good stability over bias and time comparing to un-doped ZnO-based TFTs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.49-50
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• 2005

Nitrogen and phosphorus ions were implanted into ZnO thin film fabricated by pulsed laser deposition. ion implanted ZnO thin films were annealed from $700^{\circ}C$ to $1000^{\circ}C$ using rapid thermal annealing process. The electron concentration was changed form $10^{20}$ to $10^{18}/cm^3$. Effect of nitrogen and phosphorus in ZnO thin films was certified and the structural and optical properties of nitrogen and phosphorus doped ZnO thin films depending on concentration of nitrogen and phosphorus were investigated.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.2
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• pp.9-14
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• 2009

The effects of post-annealing temperature on the optical and electrical properties of P-doped ZnO thin films grown on sapphire substrate have been investigated under oxygen ambient. The XRD shows that regardless of the post-annealing temperature, all P-doped ZnO thin films indicate the c-axis orientation. The results of hall effect measurements indicate the P-doped ZnO thin film annealed at $850^{\circ}C$ exhibits p-type behavior with hole concentration of $1.18{\times}1016cm^{-3}$ and hole mobility of $0.96cm^2/Vs$. The low-temperature (10K) Photoluminescence results reveal that the peak related to the neutral-acceptor exciton (A0X), free electrons to neutral acceptor (FA) and donor acceptor pair (DAP) at 3.351ev, 3.283eV and 3.201eV are observed in the films showing p-type behavior with acceptor. The optimization of deposition and post-annealing conditions will certainly make the P-doped ZnO thin films promising materials for the application to the next generation of optical devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.97-98
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• 2005

To investigate the ZnO thin films which is interested in the next generation of short wavelength LEDs and Lasers, our ZnO thin films were deposited by RF sputtering system. Phosphorus (P) and arsenic (As) were diffused into about 2.1${\mu}m$ ZnO thin films sputtered by RF magnetron sputtering system mn ampoule tube which was below $5\times10^{-7}$ Torr. The dopant sources of phosphorus and arsenic were $Zn_3P_2$ and $ZnAs_2$. Those diffusion was perform at 500, 600, and 700$^{\circ}C$ during 3hr. We find the condition of p-type ZnO whose diffusion condition is 700$^{\circ}C$, 3hr Our p-type ZnO thin film has not only very high carrier concentration of above $10^{19}/cm^3$ but also low resistivity of $5\times10^{-3}{\Omega}cm$.