Gate-controllable photoresponse of nitrogen-doped p-type ZnSe nanoribbons top-gate FETs

Nitrogen-doped p-type ZnSe nanoribbons (NRs) were successfully synthesized by a chemical vapor deposition (CVD) method. High-performance field-effect transistors (FETs) based on individual ZnSe NRs with high-kappa Si3N4 dielectric and top-gate geometry were constructed. In contrast to the nano-FETs with back-gate configuration and SiO2 dielectric, the top-gate FETs exhibit a substantial improvement in device performances, such as threshold voltage was reduced to a small value of 1.9 V, the transconductance, hole mobility and I-on/I-off ratio were increased to 864 nS, 10.4 cm(2) V-1 s(-1) and 10(6), respectively. Moreover, the top-gate ZnSe NR FET showed good controllability of photoresponse with fast response speed less than 0.1 s and high I-light/I-dark ratio up to 10(5), revealing that they are promising candidates for nano-electronic and optoelectronic applications. (C) 2015 Elsevier B.V. All rights reserved.