A New Method for Determining the Subgap Density of States in n-/p-Type Low-Temperature Polycrystalline-Silicon Thin-Film Transistors
- 주제(키워드) Density of States , Low-Temperature Polycrystalline-Silicon Thin-Film Transistors
- 등재 SCIE, SCOPUS
- 발행기관 AMER SCIENTIFIC PUBLISHERS
- 발행년도 2017
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000144490
- 본문언어 영어
- Published As http://dx.doi.org/10.1166/jnn.2017.14028
초록/요약
A new method for determining the acceptor-/donor-like density of states (DOS) over the entire bandgap using both the measured multi-frequency capacitance-voltage characteristics and the differential ideality factor in n-/p-type low-temperature polycrystalline-silicon thin-film transistors (LTPS TFTs) is proposed and verified. The density of deep states as a function of the gate voltage (V-gs) is obtained using the differential ideality factor, which is calculated from the transfer curves. The density of tail states as a function of V-gs is obtained using the subgap DOS-induced capacitance (C-LOC), which is calculated from the multi-frequency capacitance-voltage and resistance-voltage characteristics. The relationship between V-gs and energy, which is used to convert the DOS as a function of V-gs into the distribution of the DOS as a function of energy for device simulation, is defined using the frequency-independent gate capacitance (C-G), composed of the gate oxide capacitance (C-OX), C-LOC and the free-carrier charge induced capacitance (C-FREE). The device simulation results using the acceptor-/donor-like DOS obtained by the new method for n-/p-type LTPS TFTs exhibit excellent agreement with the measured data.
more