Controllable Synthesis Of PbSe Nanowires And Development Of PbSe MIR Detector

?-? semiconductors are direct bandgap materials.They are advanced in owning low auger coefficient,high electron mobility,long carrier lifetime and low effective mass of electron and hole.It's also possible to grow them for a large-scale on the Si basement.However,they are also disadvantaged in owning high dark current and high defect concentration.They are also poor in photoelectricity performance.This subject produce MIR detector with PbSe materials,and synthesis PbSe nanowire by CVD method.We produced the detector which can work well in normal atmospheric temperature with simple equipment and low cost.We also tested several characteristics of our PbSe detector.Our main research work is as follows:1)With the help of the Density functional theory(DFT),we calculated the band structure and density of status(DOS)of PbSe material.We then analyzed its physical property,DOS distribution and electrical characteristics.According to our calculation,the band gap of PbSe is 0.367eV,the effective mass of electron is 0.0256m0 and the effective mass of hole is 0.0213m0,all the results match well with data.2)We proposed and realized a method about synthesizing PbSe nanowire by Chemical Vapor Deposition(CVD)method,which adopt Pb as catalyzer.We plated Pb on Si base and synthesized PbSe nanowires on the Si base at the temperature of 500-600?.By changing the thickness of Pb layer,we could modify the specifications of PbSe nanowires.We then characterized the sample with Scanning Electron Microscope(SEM),Energy Dispersive Spectrometer(EDS),and Diffraction of X-rays(XRD).By this way,we could also synthesis PbSe crystalline grain on the Si base at the temperature of 300-500?.3)We produced interdigital electrode detectors.We made a huge amount of samples and selected the best of them.We then tested its Mid-infrared(MIR)and photoluminescence characters.According to the results,we calculated the voltage responsivity function.The peak responsivity is 1254V/W,which appears at the wavenumber of 3000cm-1.The Noise Equivalent Power(NEP)is 3.62×10-8W-1 and finally the Normalized Detectivity in normal atmospheric temperature is calculated to be 4.88×108cm·Hz1/2·W-1.This method only needs simple equipment and doesn't cost much.By optimizing the method,the MIR character could also improve.