In recent years,the perovskite solar cells have gained much attention because of their ever-increasing power conversion efficiency(PCE),simple solution fabrication process,flyable,light-weight wearable and deployable ...In recent years,the perovskite solar cells have gained much attention because of their ever-increasing power conversion efficiency(PCE),simple solution fabrication process,flyable,light-weight wearable and deployable for ultra-lightweight space and low-cost materials constituents etc.Over the last few years,the efficiency of perovskite solar cells has surpassed 25%due to high-quality perovskite-film accomplished through low-temperature synthesis techniques along with developing suitable interface and electrode-materials.Besides,the stability of perovskite solar cells has attracted much well-deserved attention.In this article we have focused on recent progress of the perovskite solar cells regarding their crystallinity,morphology and synthesis techniques.Also,demonstrated different layers such as electron transport-layers(ETLs),hole transport-layers(HTLs)and buffer-layers utilized in perovskite solar-cells,considering their band gap,carrier mobility,transmittance etc.Outlook of various tin(Sn),carbon and polymer-based perovskite solar cells and their potential of commercialization feasibility has also been discussed.展开更多
We report an AlGaN channel high electron mobility transistor （HEMT） on a sapphire substrate with a 1000-nm A1xGa1-xN （x = 0-0.18）/GaN composite buffer layer, With a significant improvement of crystal quality, the ...We report an AlGaN channel high electron mobility transistor （HEMT） on a sapphire substrate with a 1000-nm A1xGa1-xN （x = 0-0.18）/GaN composite buffer layer, With a significant improvement of crystal quality, the device features a high product orris. #n. The AIGaN channel HEMTs presented show improved performance with respect to the conventional AIGaN channel HEMTs, including the on-resistance reduced from 31.2 to 8.1 Ω.mm, saturation drain current at 2 V gate bias promoted from 218 to 540 mA/mm, peak transconductance at 10 V drain bias promoted from 100 to a state-of-the-art value of 174 mS/ram, and reverse gate leakage current reduced from 1.85 × 10-3 to 2.15 × 10-5 mA/mm at VOD = -20 V.展开更多
A silicon carbide （SIC） based metal semiconductor field effect transistor （MESFET） is fabricated by using a standard SiC MESFET structure with the application of a dual p-buffer layer and a multi-recessed gate to ...A silicon carbide （SIC） based metal semiconductor field effect transistor （MESFET） is fabricated by using a standard SiC MESFET structure with the application of a dual p-buffer layer and a multi-recessed gate to the process for an S-band power amplifier. The lower doped upper-buffer layer serves to maintain the channel current, while the higher doped lowerbuffer layer is used to provide excellent electron confinement in the channel layer. A 20-mm gate periphery SiC MESFET biased at a drain voltage of 85 V demonstrates a pulsed wave saturated output power of 94 W, a linear gain of 11.7 dB, and a maximum power added efficiency of 24.3% at 3.4 GHz. These results are improved compared with those of the conventional single p-buffer MESFET fabricated in this work using the same process. A radio-frequency power output greater than 4.7 W/mm is achieved, showing the potential as a high-voltage operation device for high-power solid-state amplifier applications.展开更多
文摘In recent years,the perovskite solar cells have gained much attention because of their ever-increasing power conversion efficiency(PCE),simple solution fabrication process,flyable,light-weight wearable and deployable for ultra-lightweight space and low-cost materials constituents etc.Over the last few years,the efficiency of perovskite solar cells has surpassed 25%due to high-quality perovskite-film accomplished through low-temperature synthesis techniques along with developing suitable interface and electrode-materials.Besides,the stability of perovskite solar cells has attracted much well-deserved attention.In this article we have focused on recent progress of the perovskite solar cells regarding their crystallinity,morphology and synthesis techniques.Also,demonstrated different layers such as electron transport-layers(ETLs),hole transport-layers(HTLs)and buffer-layers utilized in perovskite solar-cells,considering their band gap,carrier mobility,transmittance etc.Outlook of various tin(Sn),carbon and polymer-based perovskite solar cells and their potential of commercialization feasibility has also been discussed.
基金Supported by the National Science and Technology Major Project of China under Grant No 2013ZX02308-002National Natural Science Foundation of China under Grant Nos 11435010 and 61474086
文摘We report an AlGaN channel high electron mobility transistor （HEMT） on a sapphire substrate with a 1000-nm A1xGa1-xN （x = 0-0.18）/GaN composite buffer layer, With a significant improvement of crystal quality, the device features a high product orris. #n. The AIGaN channel HEMTs presented show improved performance with respect to the conventional AIGaN channel HEMTs, including the on-resistance reduced from 31.2 to 8.1 Ω.mm, saturation drain current at 2 V gate bias promoted from 218 to 540 mA/mm, peak transconductance at 10 V drain bias promoted from 100 to a state-of-the-art value of 174 mS/ram, and reverse gate leakage current reduced from 1.85 × 10-3 to 2.15 × 10-5 mA/mm at VOD = -20 V.
基金Project supported by the National Natural Science Foundation of China (Grant No. 61076072)
文摘A silicon carbide （SIC） based metal semiconductor field effect transistor （MESFET） is fabricated by using a standard SiC MESFET structure with the application of a dual p-buffer layer and a multi-recessed gate to the process for an S-band power amplifier. The lower doped upper-buffer layer serves to maintain the channel current, while the higher doped lowerbuffer layer is used to provide excellent electron confinement in the channel layer. A 20-mm gate periphery SiC MESFET biased at a drain voltage of 85 V demonstrates a pulsed wave saturated output power of 94 W, a linear gain of 11.7 dB, and a maximum power added efficiency of 24.3% at 3.4 GHz. These results are improved compared with those of the conventional single p-buffer MESFET fabricated in this work using the same process. A radio-frequency power output greater than 4.7 W/mm is achieved, showing the potential as a high-voltage operation device for high-power solid-state amplifier applications.
