Application Of Wavelength Sensor Based On Perovskite Nanofilm

As a new semiconductor material,perovskite has attracted the attention of researchers because of its unique structure and properties.At present,the perovskite is mainly halogen perovskite,and halogen perovskite is divided into completely inorganic perovskite and organic-inorganic hybrid perovskite.There are perovskite quantum dot,nanowires,polycrystalline film,single crystal film,large size single crystal and other forms.They have their own characteristics and are widely used in solar cells,photodetectors,lasers and other photoelectric devices.Wavelength sensor is a kind of sensor that can recognize color/spectral information.It is widely used in optical communication,image sensing,spectrometer and medical diagnosis.Most of the traditional wavelength sensors use complex filters to form a color filter array,and then through the corresponding photodetector to identify the color/spectrum.However,there are some disadvantages such as interference between channels and low quantum efficiency.Subsequently,sensors based on non-filtering chip were born one after another,but the complex manufacturing process and high cost hindered their further development.Considering all these problems,the problem of how to design a detection system with simple preparation,portability,low cost,convenient use,accurate detection and high quantum efficiency is important.This paper reports the design and testing of a novel wavelength sensitive photosensor that consists of two parallelly stacked Au/FA_0.85Cs_0.15PbI₃/Au photodetectors(PD1 and PD2),which can quantitatively distinguish incident wavelengths.Due to the dependence of wavelength and light absorption,the penetration depth of photons in perovskite nanofilms increases with the increase of wavelength.The results of computer aided design(TCAD)simulation show that the photogenerated carriers are distributed near the PD1surface when the wavelength is short,and deep on the PD2 surface when the wavelength is long.Interestingly,when the wavelength increased from 265 nm to 810 nm,the photocurrent ratio of PD1 to PD2 showed a monotonically decreasing trend.This means that the device can be used as a wavelength sensor and quantitatively detect a range of different wavelengths.The absolute error is less than 14 nm and the relative error is less than 3%,which is better than the wavelength sensors based on semiconductor materials reported in the past.It is believed that wavelength sensors based on perovskite films have potential application prospects in the future optoelectronic field.