Influence of Ammonium Chloride Buffer Solution on the Photo-Electro-Chemical (PEC) Cell and Optical Performance of Mos2 Thin Films

Abstract

Thin films of molybdenum disulphide (MoS2) of approximately same thickness of 290 nm have been successfully synthesized with and without ammonium chloride (NH4Cl) buffer solution using electrodeposition growth technique. The experimental results obtained showed that NH4Cl buffer solution has an obvious effect on the photo-electro-chemical (PEC) cell and optical performance of electrodeposited MoS2 (ED – MoS2) thin films. The MoS2 thin films prepared from NH4Cl buffer solution possess better electronic properties than the ones prepared without the buffer when measured under dark condition. Open circuit voltage of   ~0.556 V and ~0.382 V were obtained for samples prepared with and without a buffer solution respectively. MoS2 from buffer solution had higher maximum power (Pmax) of 0.710 mW while the ones without a buffer solution had a Pmax value of 0.258 mW Also, both materials showed different electrical conductivity type possibly due to the influence of chlorine in the prepared electrolytic bath. The optical results revealed similarity in the energy band gaps of both materials with a little variation. In the same vein, both MoS2 thin films showed optical conductivity of same order but MoS2 thin films prepared with buffer solution have higher magnitude than the ones without a buffer solution. These preliminary results revealed that more efficient MoS2 films for photovoltaic application can be developed / deposited using an electrolytic bath containing NH4Cl buffer.