Hyperdoped Si thin films for infrared detection

Abstract

Hyperdoped Si materials extend Si response range into near infrared by forming intermediate band in Si band gap. Ti hyperdoped Si (Si:Ti) has been demonstrated to have subbandgap photo response. In this work, we fabricated and characterized Si:Ti photodiodes and optimized the structure. At room temperature, the 3.5×10-3 EQE has been obtained at telecommunication wavelength 1550nm. And the detectable response extends until 2250nm. The results show the potential of Si:Ti materials being both Si:Ti photovoltaics and commercialized IR detection. To improve the efficiency of Si:Ti photodetectors, the affection of absorption rate, devices structure and the Si:Ti crystal quality is discussed.