• Title, Summary, Keyword: carrier mobility

Search Result 653, Processing Time 0.033 seconds

Electrical Drift Mobility in the Cholesteryl Benzoate (Cholestric 액정 Cholesteryl Benzoate에서 Drift Mobility측정)

  • 강태원;김화택
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.15 no.2
    • /
    • pp.19-21
    • /
    • 1978
  • The electrical drift mobility of charge carrier of Cholesteryl Benzoate was measured by Polarity inversion method in the temperature range 140~ 185$^{\circ}C$. with a view to revealing the mechanism of charge carrier transport. The electrical drift mobility of charge carrier of that increased from 2.5$\times$10-7$\textrm{cm}^2$/V.sec to 2.0$\times$10-6$\textrm{cm}^2$/v.sec as the temperature increased. As a result of the experiment, the mechanism of current transport is believed to be ionic mechanism.

  • PDF

Electrical Properties of TiO2 Thin Film and Junction Analysis of a Semiconductor Interface

  • Oh, Teresa
    • Journal of information and communication convergence engineering
    • /
    • v.16 no.4
    • /
    • pp.248-251
    • /
    • 2018
  • To research the characteristics of $TiO_2$ as an insulator, $TiO_2$ films were prepared with various annealing temperatures. It was researched the currents of $TiO_2$ films with Schottky barriers in accordance with the contact's properties. The potential barrier depends on the Schottky barrier and the current decreases with increasing the potential barrier of $TiO_2$ thin film. The current of $TiO_2$ film annealed at $110^{\circ}C$ was the lowest and the carrier density was decreased and the resistivity was increased with increasing the hall mobility. The Schottky contact is an important factor to become semiconductor device, the potential barrier is proportional to the hall mobility, and the hall mobility increased with increasing the potential barrier and became more insulator properties. The reason of having the high mobility in the thin films in spite of the lowest carrier concentration is that the conduction mechanism in the thin films is due to the band-to-band tunneling phenomenon of electrons.

The Degradations of Effective Mobility in Surface Channel MOS Devices (표면 채널 모스 소자에서 유효 이동도의 열화)

  • 이용재;배지칠
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.51-54
    • /
    • 1996
  • This paper reports the studies of the inversion layer mobility in p-channel Si MOSFET's under hot-carrier degradated condition. The validity of relationship of hot carrier degradations between the surface effective mobility and field effect mobility and are examined. The effective mobility(${\mu}$$\_$eff/) is derived from the channel conductances, while the field-effect mobility(${\mu}$$\_$FE/) is obtained from the transconductance. The characteristics of mobility curves can be divided into the 3 parts of curves. It was reported that the mobility degradation is due to phonon scattering, coulombic scattering and surface roughness. We are measured the mobility slope in curves with DC-stress [V$\_$g/=-3.1v]. It was found that the mobility(${\mu}$$\_$eff/ and ${\mu}$$\_$FE/) of p-MOSFET's was increased by increasing stress time and decreasing channel length. Because of the increasing stress time and increasing V$\_$g/ is changed oxide reliability and increased vertical field.

  • PDF

Mobility Determination of Thin Film a-Si:H and poly-Si

  • Jung, S.M.;Choi, Y.S.;Yi, J.S.
    • Journal of Sensor Science and Technology
    • /
    • v.6 no.6
    • /
    • pp.483-490
    • /
    • 1997
  • Thin film Si has been used in sensors, radiation detectors, and solar cells. The carrier mobility of thin film Si influences the device behavior through its frequency response or time response. Since poly-Si shows the higher mobility value, a-Si:H films on Mo substrate were subjected to various crystallization treatments. Consequently, we need to find an appropriate method in mobility measurement before and after the anneal treatment. This paper investigates the carrier mobility improvement with anneal treatments and summarizes the mobility measurement methods of the a-Si:H and poly-Si film. Various techniques were investigated for the mobility determination such as Hall mobility, HS, TOF, SCLC, TFT, and TCO method. We learned that TFT and TCO method are suitable for the mobility determination of a-Si:H and poly-Si film. The measured mobility was improved by $2{\sim}3$ orders after high temperature anneal above $700^{\circ}C$ and grain boundary passivation using an RF plasma rehydrogenation.

  • PDF

Relationship between Film Density and Electrical Properties on D.C. Magnetron Reactive Sputtered Sn-doped ${In_2}{O_3}$Films (D.C. 마그네트론 반응성 스퍼터링법에 의한 Sn-doped ${In_2}{O_3}$ 박막의 밀도와 전기적 특성과의 관계)

  • 이정일;최시경
    • Journal of the Korean Ceramic Society
    • /
    • v.37 no.7
    • /
    • pp.686-692
    • /
    • 2000
  • Tin-doped In2O3 (ITO) films were fabricated using a d.c. magnetron reactive sputteirng of a In-10 wt% Sn alloy target in an Ar and O2 gas mixture. To understand the behavior of the carrier mobility in ITO films with O2 partial pressure, the resistivity, carrier concentration and mobility, film density, and intrinsic stress in the films were measured with O2 partial pressure. It was found experimentally that the carrier mobility increased rapidly as the film density increased. In the ITO film with the density close to theoretical one, the mean free path was the same as the columnar diameter. This indicated that the mobility in ITO films was strongly influenced by the crystall size. However, in the case where the film density was smaller than a theoretical density, the mean free paths were also smaller the columnar diameter. It was analyzed that the electron scattering at pores and holes within the crystalline was the major obstacle for electron conduction in ITO films. The measurement of intrinsic stress in ITO films also made it clear that the density of ITO films was controlled by the bombardment of oxygen neutrals on the growing film.

  • PDF

Transport phenomena of a-Se:As thin film for digital X-ray Conversion Material (디지털 X-선 변환물질을 위한 비소(As) 첨가 비정질 셀레늄(a-Se) 박막의 수송현상)

  • Park, Chang-Hee;Kim, Jae-Hyung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.282-283
    • /
    • 2006
  • The transport phenomena of arsenic (As) doped amorphous selenium(a-Se:As) thin film for digital X-ray conversion material has been reported. The effect of As addition on the carrier mobility and recombination lifetime in a-Se:As sample has been measured using the moving photo-carrier grating (MPG) technique. An Increase in hole mobility and recombination was observed when 0.3% arsenic, was added into a-Se sample, whereas electron mobility decrease with arsenic addition due to the defect density. The fabricated a-Se:03% As device exhibited the highest X-ray sensitivity.

  • PDF

2D printed graphene conductive layers with high carrier mobility

  • Yakimchuk, Evgenyi;Soots, Regina;Kotin, Igor;Antonova, Irina
    • Current Applied Physics
    • /
    • v.17 no.12
    • /
    • pp.1655-1661
    • /
    • 2017
  • The comparison of different suspensions, obtained from the same material source subjected to electrochemical exfoliation and to analogous auxiliary treatments, but in different solutions, allowed choosing the most effective approach to obtaining graphene suspensions. It was found for the layers with a thickness of 10-20 nm printed from a water-based suspension that the sheet resistance was $5-10k{\Omega}/{\square}$, and the carrier mobility was equal to $30-40cm^2/V{\cdot}s$. The most important parameter determining the mobility of carriers in the films obtained from suspensions is found to be the flake thickness. The carrier mobility strongly decreased from ~100 to $0.05cm^2/V{\cdot}s$ when the flake thickness changed from one monolayer to few monolayers (up to ~ 4-5 nm). This effect is most likely associated with the quality of the connection between the flakes. Only monolayer - bilayer flakes are capable of forming real connections in the film due to van-der-Waals forces.

Transport Properties of Conversion Materials for Digital Radiography

  • Kim, Jae-Hyung;Park, Chang-Hee;Nam, Sang-Hee
    • Transactions on Electrical and Electronic Materials
    • /
    • v.8 no.6
    • /
    • pp.250-254
    • /
    • 2007
  • Applying the moving photo-carrier grating(MPG) technique and time-of-flight(TOF) measurements, we studied the transport properties of stabilized amorphous selenium typical of the material used in direct conversion X-ray imaging devices. For MPG measurement, we obtained electron and hole mobility and the recombination lifetime of $\alpha-Se$ films with arsenic(As) additions. We found an apparent increase in hole drift mobility and recombination lifetime, especially when 0.3 % As was added into $\alpha-Se$ film, whereas electron mobility decreased with the addition of As due to the defect density. For TOF measurement, a laser beam with pulse duration of 5 ns and wavelength of 350 nm was illuminated on the surface of $\alpha-Se$ with a thickness of 400 ${\mu}m$. The measured hole and electron transit times were about 8.73 ${\mu}s$ and 229.17 ${\mu}s$, respectively.

Theoretical insight into the carrier mobility anisotropy of hole transport material Spiro-OMeTAD

  • Meng, Guanghao;Shi, Yantao;Song, Xuedan;Ji, Min;Xue, Yuan;Hao, Ce
    • Current Applied Physics
    • /
    • v.17 no.10
    • /
    • pp.1316-1322
    • /
    • 2017
  • All-solid-state organic-inorganic halide perovskite solar cells (PSCs) have attracted wide attention due to the rapid progress of power conversion efficiency in recent years. Hole transport material (HTM) in PSCs plays the role of extracting and transporting photo-excited holes. Anisotropy of carrier mobility is one important property for semiconductors, however, which still remains unclear for the dominant HTM spiro-OMeTAD used in PSCs. Based on Density Functional Theory (DFT) and Marcus theory, we for the first time conducted investigations on the anisotropy of carrier mobility along representative crystal planes of spiro-OMeTAD by recombination energy ${\lambda}$ and electronic coupling integral V. Results indicate that the holes and electrons show transport orientations consistency parallel to the (010), (101) and (111) crystal planes while inconsistency was found parallel to (100), (110), (011) and (001) crystal planes (with an angle ranged from $40^{\circ}$ to $70^{\circ}$ between the hole and electron transport directions). Our work embodies the theoretical significance of controllable and oriented fabrication of HTM in PSCs.