Enhancement of Solar Cell Performance of Electrodeposited Ti/n-Cu2O/p-Cu2O/Au Homojunction Solar Cells by Interface and Surface Modification

Abstract

Cuprous oxide (Cu2O) homojunction thin films on Ti substrates were fabricated by an electrochemical deposition in which a p-Cu2O layer was deposited on an n-Cu2O layer by carefully controlled bath conditions. It was found that the open-circuit voltage of the homojunction solar cell was significantly influenced by the pH of the lactate bath. The variation of the pH was used to achieve the best possible crystal orientation for homojunctions. The crystallinity and morphology of the products were characterized by X-ray diffraction (XRD), high-energy x-ray diffraction (HEXRD), and scanning electron microscopy (SEM). The current density voltage (J-V) analysis showed that the sulfur treatment and annealing enhanced the photocurrent by ten-fold compared to the untreated and unannealed homojunction solar cell. X-ray photoelectron spectroscopy (XPS) studies confirmed that the sulfur treatment eliminated the surface CuO and formed a thin layer of CuS, which was very useful to make the front Ohmic contact. Transient measurements confirmed that the p-type Cu2O layer, which was subjected to sulfur treatment, significantly reduced the recombination, thus enhancing the efficiency of the solar cell. The best sulfur treated annealed Ti/n-Cu2O/p-Cu2O/Au solar cell produced an energy conversion efficiency of 2.64% with an open-circuit voltage of 490 mV and a short circuit current density of 12.8 mA cm−2 under AM 1.5 illumination.

Optimizing the structure and optoelectronic properties of cuprite thin films via a plasma focus device as a solar cell absorber layer

“…[12][13][14] Characterized as a p-type semiconductor, Cu 2 O, with a direct bandgap ranging from 2.0 to 2.4 eV, 15 aptly suits its role as an absorber layer in solar cells. 16 The efficacy of Cu 2 O-based solar cells is contingent upon many factors, including the quality of the Cu 2 O thin films, 17 the positioning of the band at the interface between Cu 2 O and adjacent layers, 18 and the overall architecture of the device. 19 Consequently, the deposition of high-quality Cu 2 O thin films is paramount to developing proficient Cu 2 O-based solar cells.…”

Influence of Annealing Process on Cu2O Nanofilm and the Efficiency of Annealed p-Cu2O/n Si Nanostructure Solar Cell Prepared by Thermal Evaporation Technique

“…Tuama et al [17] prepared Cu2O: Ag NPs/Si solar cell by the technique of thermal evaporation and the conversion efficiency that they obtained of 3.5 by Cu2O: 0.04 Ag NPs/Si. Jayathilaka et al [18] deposited Cu2O homojunction thin film onto a Ti substrate by an electrochemical deposition technique and the gained conversion efficiency of 2.64%, under AM1.5 illumination, were achieved by an annealed sulfur-treated solar cell of Ti/n-Cu2O/p-Cu2O/Au. Abdurrahman et al [19] fabricated a photoactive substance comprising of Bi/Cu2O/Bi solar cell by using a thermal oxidation process and method of powder vaporization, and the fabricated cell produced a power conversion efficiency of 1.14%.…”

Enhancement of Structural, Optical and Photoelectrochemical Properties of n−Cu2O Thin Films with K Ions Doping toward Biosensor and Solar Cell Applications

“…Cu 2 O generally has the characteristic behavior of a p-type semiconductor owing to an acceptor level created by copper ion vacancies formed above the valence band at about 0.4 eV. Donor levels created by oxygen vacancies below the conduction band bottom at about 0.38 eV indicate the presence of a Cu 2 O n-type semiconductor [ 3 ]. Cu 2 O exhibits a direct band gap of about 2 eV, an abundance of source materials, non-toxicity and an extremely high absorption coefficient [ 4 , 5 ].…”