silicon nanowires (SiNWs) with well orientation and crystallization are synthesized by the vapor-liquid-solid (VLS) process, and doped as n-type by an ex situ process using spin on dopant (SOD) technique. The ex situ doping process using SOD was based on solid-state diffusion, which comprised two stages: pre-coating and drive in. The phosphorous concentration in SiNWs was controlled by appropriate selections of the drive in temperature and the time period, which are 950 °C and 5-60 min in the present studies. The doped nanowire can be readily made into a temperature sensor with much better resolution and response. Calibration of the SiNW temperature sensor at different doping level has been performed. With a concentration of 4 × 1015 atoms/cm 3 the SiNW sensor has the best temperature resolution (6186 Ω/ °C) and sensitivity in this study.