Bi_(2)O_(2)Se is highly competitive as a candidate of next-generation high-performance semiconductors.Though dubbed as semiconductor,Bi_(2)O_(2)Se films exhibited high conductance,i.e.,metallic behavior,due to spontan...Bi_(2)O_(2)Se is highly competitive as a candidate of next-generation high-performance semiconductors.Though dubbed as semiconductor,Bi_(2)O_(2)Se films exhibited high conductance,i.e.,metallic behavior,due to spontaneously ionized defects.Semiconducting/insulating films are of practical importance in broad applications based on low-power,high-performance electronics,the existence of which lacks firm evidence.Here,we synthesized highly insulating films in a controlled way,which exhibit semiconducting behavior with channel resistance up to 1 TΩ.The electron chemical potential lies within the band gap,in some cases,even below the charge neutrality level,signifying the trace of hole-type semiconducting.The performance of insulating devices remains high,comparable to high-quality devices previously.Especially,the threshold voltage(Vth)is positive,contrary to common negative values reported.Calculations indicate that our synthesis conditions suppress electron donors(Se vacancies(VSe))and promote the formation of compensating acceptors(Bi vacancies(VBi)),leading to insulating behaviors.Our work offers insights into electron dynamics of Bi_(2)O_(2)Se,moves one step further towards p-type transistors and provides a valuable playground for engineering ferroelectricity in high-performance semiconductors.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11904294 and 62004172)the foundation of Westlake Multidisciplinary Research Initiative Center(MRIC,Nos.MRIC20200402 and 20200101).
文摘Bi_(2)O_(2)Se is highly competitive as a candidate of next-generation high-performance semiconductors.Though dubbed as semiconductor,Bi_(2)O_(2)Se films exhibited high conductance,i.e.,metallic behavior,due to spontaneously ionized defects.Semiconducting/insulating films are of practical importance in broad applications based on low-power,high-performance electronics,the existence of which lacks firm evidence.Here,we synthesized highly insulating films in a controlled way,which exhibit semiconducting behavior with channel resistance up to 1 TΩ.The electron chemical potential lies within the band gap,in some cases,even below the charge neutrality level,signifying the trace of hole-type semiconducting.The performance of insulating devices remains high,comparable to high-quality devices previously.Especially,the threshold voltage(Vth)is positive,contrary to common negative values reported.Calculations indicate that our synthesis conditions suppress electron donors(Se vacancies(VSe))and promote the formation of compensating acceptors(Bi vacancies(VBi)),leading to insulating behaviors.Our work offers insights into electron dynamics of Bi_(2)O_(2)Se,moves one step further towards p-type transistors and provides a valuable playground for engineering ferroelectricity in high-performance semiconductors.
