| 1. |
- Liu, Jinghuang, et al.
(författare)
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Effect of iodine doping on photoelectric properties of perovskite-based MOS devices
- 2020
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Ingår i: Materials letters (General ed.). - : ELSEVIER. - 0167-577X .- 1873-4979. ; 261
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Tidskriftsartikel (refereegranskat)abstract
- In this article, the PVK based metal-oxide-semiconductor (MOS) capacitor structures were fabricated and the photoelectric performance of the capacitor was carried out to study the intrinsic electrical characteristic of PVK with iodine doped. The electrical hysteresis of the capacitor after iodine doping becomes larger in the dark state, which indicates that the hysteresis behavior of the PVK is caused by the mobile iodine ions. The photocurrent of iodine-doped PVK is significantly greater than that of undoped PVK under illumination, which suggests that the capacitor has better response to light and the photodetectors efficiency also increase after iodine doping. Our results provide a theoretical basis for the potential application of memory devices such as memristors under dark. Meanwhile, it provides a method to improve photodetector performance by adding an appropriate amount of iodine to the PVK precursor solution. (C) 2019 Elsevier B.V. All rights reserved.
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| 2. |
- Pang, Tiqiang, et al.
(författare)
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Hysteresis effects on carrier transport and photoresponse characteristics in hybrid perovskites
- 2020
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Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 8:6, s. 1962-1971
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Tidskriftsartikel (refereegranskat)abstract
- Organic-inorganic hybrid perovskites have recently emerged as promising potential candidate materials in the area of photoelectrics due to their unparalleled optoelectronic features. However, the performance of an optoelectronic device is always affected by the mixed ionic and electronic conducting behavior within perovskites. Herein, the hysteresis effect on carrier mobility and photoresponse characteristics of perovskites were investigated through adding rational additives to the precursor solution. The results show that the perovskite with foreign fullerene derivative (PCBM) additive can suppress hysteresis behavior and increase the mobility by two-fold, while the perovskite with native iodine (I) additive will amplify hysteresis and reduce the mobility by two orders of magnitude at the room temperature compared with that of the pure perovskite. Furthermore, we found that the response characteristics of the photodetectors are strongly affected by the carrier mobility. Capacitance-voltage results confirm the significant change in hysteresis after the introduction of different additives, which explains the changes in mobility and photoresponse time. Our results enlighten the hysteresis effect related to carrier transport and photoresponse characteristics, and provide guidance for the development of reliable, high performance perovskite devices.
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| 3. |
- Zhang, Hongpeng, et al.
(författare)
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Influence of Metal Gate Electrodes on Electrical Properties of Atomic-Layer-Deposited Al-Rich HfAlO/Ga2O3 MOSCAPs
- 2020
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Ingår i: IEEE Transactions on Electron Devices. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0018-9383 .- 1557-9646. ; 67:4, s. 1730-1736
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Tidskriftsartikel (refereegranskat)abstract
- As the p-type doping beta-Ga2O3 is absent up to now, metal gate (MG) stacks with high work functions are expected to benefit the fabrication of normally-OFF beta-Ga2O3 transistors. In this article, the electrical characteristics of beta-Ga2O3 metal-electrode-gated metal-oxidesemiconductor (MOS) deviceswith Al-rich HfAlO dielectrics and different MG stacks (Ni, Au, Pt, and Ti) are evaluated. The interface state density (Dit) of HfAlO/ beta-Ga2O3 interface is characterized based on the frequency-dependent capacitance-voltage (C-V) and photo-assisted deep ultraviolet (DUV) C-V measurements. An average Dit of 4.45 x 10(11) eV(-1)cm(-2) is extracted from the photo-assisted (deep UV) C-V measurement, while a large amount of border traps, negative fixed charges, and deep traps is also induced at the oxide layer and/or HfAlO/beta-Ga2O3 interface. Then, this article investigates the evaluations of Ti, Ni, Au, and Pt as candidate MGs for beta-Ga2O3 MOS using Al-rich HfAlO as gate dielectric. The obvious flat-band voltage (V-FB) shift and gate leakage variation are observed in beta-Ga2O3 capacitors with different MG solutions, indicating that HfAlO dielectric combined with Ni, Au, and Pt MGs is promising to facilitate some beneficial modifications of normally-OFF beta-Ga2O3 transistors, while Ti electrode ismore suitable for normally-ON beta-Ga2O3 transistors. This article provides an additional practical guideline for choosing the appropriate MG stacks and potential gate dielectric to the development of normally-OFF Ga2O3 transistors.
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| 4. |
- Zhang, Hongpeng, et al.
(författare)
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Progress of Ultra-Wide Bandgap Ga < sub > 2 O < sub > 3 Semiconductor Materials in Power MOSFETs
- 2020
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Ingår i: IEEE transactions on power electronics. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0885-8993 .- 1941-0107. ; 35:5, s. 5157-5179
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Tidskriftsartikel (refereegranskat)abstract
- As a promising ultra-wide bandgap semiconductor, the <italic>& x03B2;</italic>-phase of Ga<sub>2</sub>O<sub>3</sub> has attracted more and more interest in the field of power electronics due to its ultra-wide bandgap (4.8 & x00A0;eV), high theoretical breakdown electric field (8 MV & x002F;cm), and large Baliga & x0027;s figure of merit, which is deemed as a potential candidate for next generation high-power electronics, including diodes, field effect transistors (FETs), etc. In this article, we introduce the basic material properties of Ga<sub>2</sub>O<sub>3</sub>, and review the recent progress and advances of <italic>& x03B2;</italic>-Ga<sub>2</sub>O<sub>3</sub> based metal & x2013;oxide & x2013;semiconductor field-effect transistors (<sc>mosfet</sc>s). Due to the problematic p-type doping technology up to now, the enhancement-mode (E-mode) <italic>& x03B2;</italic>-Ga<sub>2</sub>O<sub>3</sub> FETs face more difficulties, compared with depletion mode (D-mode). This article focuses on reviewing the recent progress of E-mode Ga<sub>2</sub>O<sub>3</sub> <sc>mosfet</sc>s, summarizing and comparing various feasible solutions when p-type doping is absent. Furthermore, the device fabrication and performances of state-of-art <italic>& x03B2;</italic>-Ga<sub>2</sub>O<sub>3</sub> <sc>mosfet</sc>s, including D-mode, E-mode, and planar & x002F;vertical structure are fully discussed and compared, as well as potential solutions to the challenges of Ga<sub>2</sub>O<sub>3</sub> FETs.
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