“Infinite Sensitivity” of Black Silicon Ammonia Sensor Achieved by Optical and Electric Dual Drives

Abstract

The microstructured and hyperdoped silicon as a superior photoelectric and photovoltaic material is first studied as a gas-sensing material. The material is prepared by femtosecond-laser irradiation on selenium-coated silicon and then fabricated as a conductive gas sensor, targeting ammonia. At room temperature, the sensitivity, response time, repeatability, distinguishability, selectivity, and natural aging effect of the sensor have been systematically studied. Results show that such black silicon has good potential for application as an ammonia-sensing material. On the basis of its unique optoelectronic properties, an additional optical drive is proposed for the formation of an optical and electric dual-driven sensor, which is achieved by asymmetric light illumination between the two electrode regions. In a certain range of applied voltage, the sensitivity is enhanced dramatically and even tends to be infinite. For the aged device with degraded sensitivity, a two-order increment is obtained for 500 ppm of NH under the extra optical drive. A mechanism based on Dember effect is proposed for explaining such a phenomenon.

Recent Progress of Black Silicon: From Fabrications to Applications

“…In 2018, X. Liu [108] first proposed the use of black silicon materials as gas sensing materials. Based on the excellent photoelectric characteristics of the black silicon material, the researchers realized the dual drive sensor of light and electricity by asymmetrically illuminating the two electrode regions.…”

“…In 2020, S. Iakab [110] fabricated a black silicon substrate modified with gol particles for surface-assisted laser desorption/ionization mass spectrometry imagi [108], with permission from American Chemical Society © 2020. (b) Experimental setup for black silicon nanostructures current monitoring.…”

Surgical management of breast cancer in China: the Fudan University Shanghai Cancer Center experience

“…Recently, the lateral photovoltaic effect found application also in the self-powered gas sensing [98]- [101]. X.-L. Liu et al proposed a self-powered ammonia gas sensor using the sulfur-hyperdoped silicon [99].…”

Black Silicon Photodetector with Excellent Comprehensive Properties by Rapid Thermal Annealing and Hydrogenated Surface Passivation

“…Recently, ultrafast laser hyperdoped silicon (b‐Si) has attracted much interest due to its distinctive properties and potential for a range of applications . In particular, b‐Si materials hyperdoped with chalcogens (e.g., S, Se, and Te) or transition metals (e.g., Ag, Au, and Ti) have gained considerable attention due to their strong visible and infrared absorption, with great potential in intermediate‐band solar cells, light emitters, gas sensors, and photodetectors . Devices fabricated with these materials have shown a remarkable enhancement in photon responsiveness, typically some orders of magnitude higher than that of traditional silicon photodetectors at low bias voltage.…”