Preparation Of Mn Ion Substitution Substitution Cu₂ZnSnS₄ Material And Its Response In The Terahertz Frequency Band

The Cu₂ZnSnS₄?CZTS?thin film is considered as one of the most suitable absorbing layer materials for thin film solar cells due to its proper band gap,high optical absorption coefficient and non-toxic\earth-abundant raw materials.In this paper,the manganese substituted copper zinc tin sulfide nano-powder was synthesized by gradually heating method.And EDX,XRD,Raman,UV-Vis and HRTEM techniques were used to analyze the optical properties,particle composition,particle composition,phase structure phase structure and morphology of all samples.The results showed that the materials still maintain good absorption in the visible light wavelength along with the increase of the amount of manganese substituting,and the optical band gap is reduced from 1.50 eV to 1.30 eV,which is a suitable band gap for solar cells.It is found that the Cu₂ZnSnS₄ samples could transform from wurtzite structure to Stannite Cu₂MnSnS₄ structure along with the increase of Mn substituting amount.The average particle size of the samples obtained by HRTEM detection is about 10nm,and the particle size is showed uniformed.The dispersion also is very good.The crystal spacing between the samples obtained is consistent with the detection results of XRD and Raman.The as-prepared materials own excellent properties of adjustable band gaps and phase transformed.The THz-TDS system was used to detect the different content of Mn substituted samples and different elements substituting samples in terahertz band ranged 0.5³ THz.A series of optical information including the THz spectra of the samples,refractive index,extinction coefficient,relative permittivity and conductivity of the samples were calculated.The OPTP system was used to detect the different content of Mn substituted samples,and the carrier information of all samples was showed in the paper,which obtain the sample carrier concentration and carrier life time.