Fabrication and characterization of p-lanthanum sulphide/n-CdS Heterojunction

Abstract

Abstract: The p-n heterojunction p-La₂S₃/n-CdS was fabricated by the depositing of La₂S₃ thin film onto Fluorine doped tin oxide  (FTO) coated glass substrate by spray pyrolysis technique over which CdS was deposited  by successive ionic layers and adsorption and reaction (SILAR) method. The FTO coated glass substrate was used  as back contact (La₂S₃) p-electrode and press front contact was used (for CdS) as n-electrode.  The electrical properties of a heterojunction such as current-voltage (I-V) and capacitance-voltage (C-V) characteristics give the information regarding type of heterojunction and device usefulness.  I-V and    C-V characteristics of p-lanthanum chalcogenide/n-CdS junction diode device was studied. The nature of I-V characteristics indicates the formation of rectifying junction. The value of junction ideality factors was estimated and found much larger than ideality diode values. The value of negative flat band potential (V_fb= - 600) was calculated and found to be p type conductivity.