Study On Lateral Photovoltaic Properties Of Tin Diselenide Film

With the rapid development of biotechnology and nanotechnology,the demand for high-performance position sensitive sensors based on lateral photovoltaic effect is becoming more and more intense,and has important applications in biomedical and biological detection.The new two-dimensional layered SnSe2 material is an n-type narrow bandgap semiconductor with excellent physical and chemical properties.It is a highly sensitive and fast photoresponsive sensor device in recent years.The lateral photovoltaic properties of samples based on SnSe2 thin film materials have certain value for further improving the lateral photovoltaic performance of thin film materials and developing higher sensitivity and faster response time sensor.In this paper,a series of nano-sized SnSe2 thin films were grown on p-type silicon substrates by pulsed laser deposition;The effect of different electrode spacing on the lateral photovoltaic properties of the sample at a laser wavelength of 645 nm and a film thickness of 10 nm was investigated.When the electrode spacing is 1.6 mm,the lateral photovoltaic value has a good linear relationship with the illumination position,and has a position sensitivity of up to 364.5 mV/mm;By studying the influence of laser power and wavelength on the lateral photovoltaic properties of the sample,it is proved that the origin of lateral photovoltaic is photoelectric effect rather than thermal effect;The influence of different external resistors on the optical response time of SnSe2 film was compared and analyzed.It was found that the relaxation time decreased with the decrease of external resistance.When the external 4.6 k?resistor is connected,a fast response time of 120 ns and a relaxation time of 3.07 ?s are obtained;By studying the lateral ?-? curve of the sample,the reason why the SnSe2 film produces a fast photoresponse is that the inversion layer formed at the SnSe2/p-Si interface provides a low-resistance conductive path.