Effective performance for undoped and boron-doped double-layered nanoparticles-copper telluride and manganese telluride on tungsten oxide photoelectrodes for solar cell devices

Abstract

This work demonstrates the synthesis of a novel double-layered Cu2−xTe/MnTe structure on a WO3 photoelectrode as a solar absorber for photovoltaic devices. Each material absorber is synthesized using a successive ionic layer adsorption and reaction (SILAR) method. The synthesized individual particle sizes are Cu2−xTe(17) ∼5–10 nm and MnTe(3) ∼2 nm, whereas, the aggregated particle sizes of undoped and boron-doped Cu2−xTe(17)/MnTe(11) are ∼50 and 150 nm, respectively. The larger size after doping is due to the interconnecting of nanoparticles as a network-like structure. A new alignment of the energy band is constructed after boron/MnTe(11) is coated on boron/Cu2−xTe nanoparticles (NPs), leading to a narrower Eg equal to 0.58 eV. Then, the valence band maximum (VBM) and conduction band minimum (CBM) with a trap state are also up-shifted to near the CBM of WO3, leading to the shift of a Fermi level for ease of electron injection. The best efficiency of 1.41% was yielded for the WO3/boron-doped [Cu2−xTe(17)/MnTe(11)] structure with a photocurrent density (Jsc) = 16.43 mA/cm2, an open-circuit voltage (Voc) = 0.305 V and a fill factor (FF) = 28.1%. This work demonstrates the feasibility of this double-layered structure with doping material as a solar absorber material.