Wafer-scale synthesis of p-type TMD films is critical for its commercialization in next-generation electro/optoelectronics.In this work,wafer-scale intrinsic n-type WS_(2)films and in situ Nb-doped p-type WS_(2)films ...Wafer-scale synthesis of p-type TMD films is critical for its commercialization in next-generation electro/optoelectronics.In this work,wafer-scale intrinsic n-type WS_(2)films and in situ Nb-doped p-type WS_(2)films were synthesized through atomic layer deposition(ALD)on 8-inchα-Al_(2)O_(3)/Si wafers,2-inch sapphire,and 1 cm^(2)GaN substrate pieces.The Nb doping concentration was precisely controlled by altering cycle number of Nb precursor and activated by postannealing.WS_(2)n-FETs and Nb-doped p-FETs with different Nb concentrations have been fabricated using CMOS-compatible processes.X-ray photoelectron spectroscopy,Raman spectroscopy,and Hall measurements confirmed the effective substitutional doping with Nb.The on/off ratio and electron mobility of WS_(2)n-FET are as high as 105 and 6.85 cm^(2)V^(-1)s^(-1),respectively.In WS_(2)p-FET with 15-cycle Nb doping,the on/off ratio and hole mobility are 10 and 0.016 cm^(2)V^(-1)s^(-1),respectively.The p-n structure based on n-and p-type WS_(2)films was proved with a 10^(4)rectifying ratio.The realization of controllable in situ Nb-doped WS_(2)films paved a way for fabricating wafer-scale complementary WS_(2)FETs.展开更多
Wafer-scale synthesis of p-type TMD films is critical for its commercialization in next-generation electro/optoelectronics.In this work,wafer-scale intrinsic n-type WS_(2)films and in situ Nb-doped p-type WS_(2)films ...Wafer-scale synthesis of p-type TMD films is critical for its commercialization in next-generation electro/optoelectronics.In this work,wafer-scale intrinsic n-type WS_(2)films and in situ Nb-doped p-type WS_(2)films were synthesized through atomic layer deposition(ALD)on 8-inchα-Al_(2)O_(3)/Si wafers,2-inch sapphire,and 1 cm^(2)GaN substrate pieces.The Nb doping concentration was precisely controlled by altering cycle number of Nb precursor and activated by postannealing.WS_(2)n-FETs and Nb-doped p-FETs with different Nb concentrations have been fabricated using CMOS-compatible processes.X-ray photoelectron spectroscopy,Raman spectroscopy,and Hall measurements confirmed the effective substitutional doping with Nb.The on/off ratio and electron mobility of WS_(2)n-FET are as high as 105 and 6.85 cm^(2)V^(-1)s^(-1),respectively.In WS_(2)p-FET with 15-cycle Nb doping,the on/off ratio and hole mobility are 10 and 0.016 cm^(2)V^(-1)s^(-1),respectively.The p-n structure based on n-and p-type WS_(2)films was proved with a 10^(4) rectifying ratio.The realization of controllable in situ Nb-doped WS_(2)films paved a way for fabricating wafer-scale complementary WS_(2)FETs.展开更多
Acrylamide copolymers are often used as acidizing diverting and thickening agents for their advantageous thickening,flocculation,adhesion and resistance reduction properties.Experimental results indicate that the acid...Acrylamide copolymers are often used as acidizing diverting and thickening agents for their advantageous thickening,flocculation,adhesion and resistance reduction properties.Experimental results indicate that the acid concentration greatly affects the properties of acrylamide polymers,which varies from results reported by other researchers.Considering the theoretical and field application value of the present study,four comparable acrylamide-based polymers were synthesized,and their macro-and micro-changes as well as the related changes in viscosity and molecular weight were studied in high-concentration hydrochloric acid.A proposed mechanism of acrylamide copolymer stability and degradation is provided,and further suggestions are made for the modification of acrylamide copolymers.展开更多
基金supported by the NSFC(62004044 and 61904033)by State Key Laboratory of ASIC&System(2021MS004)This research was partially supported by the National Science Foundation through the Center for Dynamics and Control of Materials:an NSF MRSEC under Cooperative Agreement No.DMR-1720595。
文摘Wafer-scale synthesis of p-type TMD films is critical for its commercialization in next-generation electro/optoelectronics.In this work,wafer-scale intrinsic n-type WS_(2)films and in situ Nb-doped p-type WS_(2)films were synthesized through atomic layer deposition(ALD)on 8-inchα-Al_(2)O_(3)/Si wafers,2-inch sapphire,and 1 cm^(2)GaN substrate pieces.The Nb doping concentration was precisely controlled by altering cycle number of Nb precursor and activated by postannealing.WS_(2)n-FETs and Nb-doped p-FETs with different Nb concentrations have been fabricated using CMOS-compatible processes.X-ray photoelectron spectroscopy,Raman spectroscopy,and Hall measurements confirmed the effective substitutional doping with Nb.The on/off ratio and electron mobility of WS_(2)n-FET are as high as 105 and 6.85 cm^(2)V^(-1)s^(-1),respectively.In WS_(2)p-FET with 15-cycle Nb doping,the on/off ratio and hole mobility are 10 and 0.016 cm^(2)V^(-1)s^(-1),respectively.The p-n structure based on n-and p-type WS_(2)films was proved with a 10^(4)rectifying ratio.The realization of controllable in situ Nb-doped WS_(2)films paved a way for fabricating wafer-scale complementary WS_(2)FETs.
基金supported by the NSFC(62004044 and 61904033)and by State Key Laboratory of ASIC&System(2021MS004)This research was partially supported by the National Science Foundation through the Center for Dynamics and Control of Materials:an NSF MRSEC under Cooperative Agreement No.DMR-1720595.
文摘Wafer-scale synthesis of p-type TMD films is critical for its commercialization in next-generation electro/optoelectronics.In this work,wafer-scale intrinsic n-type WS_(2)films and in situ Nb-doped p-type WS_(2)films were synthesized through atomic layer deposition(ALD)on 8-inchα-Al_(2)O_(3)/Si wafers,2-inch sapphire,and 1 cm^(2)GaN substrate pieces.The Nb doping concentration was precisely controlled by altering cycle number of Nb precursor and activated by postannealing.WS_(2)n-FETs and Nb-doped p-FETs with different Nb concentrations have been fabricated using CMOS-compatible processes.X-ray photoelectron spectroscopy,Raman spectroscopy,and Hall measurements confirmed the effective substitutional doping with Nb.The on/off ratio and electron mobility of WS_(2)n-FET are as high as 105 and 6.85 cm^(2)V^(-1)s^(-1),respectively.In WS_(2)p-FET with 15-cycle Nb doping,the on/off ratio and hole mobility are 10 and 0.016 cm^(2)V^(-1)s^(-1),respectively.The p-n structure based on n-and p-type WS_(2)films was proved with a 10^(4) rectifying ratio.The realization of controllable in situ Nb-doped WS_(2)films paved a way for fabricating wafer-scale complementary WS_(2)FETs.
文摘Acrylamide copolymers are often used as acidizing diverting and thickening agents for their advantageous thickening,flocculation,adhesion and resistance reduction properties.Experimental results indicate that the acid concentration greatly affects the properties of acrylamide polymers,which varies from results reported by other researchers.Considering the theoretical and field application value of the present study,four comparable acrylamide-based polymers were synthesized,and their macro-and micro-changes as well as the related changes in viscosity and molecular weight were studied in high-concentration hydrochloric acid.A proposed mechanism of acrylamide copolymer stability and degradation is provided,and further suggestions are made for the modification of acrylamide copolymers.
