A Narrow Band Photodetector Based On Organic Dye Sensitization

Photodetectors are the important component in the connection of optics and electricity,widely used in imaging,communication and environmental monitoring.According to the spectral classification,the detector can be divided into wide-spectrum detection and narrow-band detection,and the narrow-band detector can be used for biomarkers and 3D face recognition.According to the vibration mode,the detector can be divided into polarization sensitive photoelectric detection and non-polarized photoelectric detection,and polarization detection can be used in the field of atmospheric monitoring and night vision.Because of its special molecular structure and spatial configuration,organic semiconductor materials can effectively perceive the amplitude(intensity),frequency(wavelength)and vibration direction(polarization)information of light waves.Dye molecules is a kind of natural narrow-band absorption material,which can be used for the preparation of high-performance narrowband photoelectric detector,the photoelectric conversion process of the detector similar to organic dye sensitized solar cell,has a wide source of the dye.However,the response of photoconductive dye detector is relatively low,usually several hundred mA/W,which is caused by the low mobility of dye molecules and the inability of photogenic carriers to be efficiently collected.In order to improve the photoelectric performance parameters of the detector,we introduce the graphene transport layer,prepare the hybrid dye sensitization narrowband detector,and increase the response of the device by four orders of magnitude.The main research contents of this paper are as follows.To study the photoelectric detector of "dye molecule/nano particle/transport layer" structure.BODIPYs dye BET is used as the detector's functional active layer to realize narrowband absorption of target frequency.UV-Vis spectrophotometer was used to characterize the spectral properties of dyes.The narrow band absorption characteristics of the device were obtained by optimizing the adsorption time of dye molecules and the thickness of the nanoparticles.The characteristic parameters of the narrow-band detector are optimized by means of encapsulation and gate control,especially for the response time.In this paper,the dual-peak narrow-band photodetector was made and flexible PET substrate are introduced to realize flexible photoelectric detection.The noise of the detector is studied in detail by the SR 850 digital phase-locked amplifier,and the ratio detection rate of the device is obtained.Finally,based on this structure,we introduce chlorophyll copper sodium salt molecules as polarization sensitive active layer,prepare dye-sensitized polarized photoelectric detector,and realize multi-dimensional detection of optical signals.