Review of the development of copper oxides with titanium dioxide thin-film solar cells

Abstract

Copper oxide-titanium dioxide (TiO 2) p–n junctions are promising materials for photovoltaic devices and may reduce production costs due to their low cost and inexpensive production methods compared with silicon solar cells. The present review compares solar cells made with copper oxides combined with TiO 2–TiO 2/Cu 2O and TiO 2/CuO heterojunctions, and “cascade heterojunction systems.” First, we describe the main properties of titanium (iv) dioxide (TiO 2), cuprous oxide (Cu 2O), and cupric oxide (CuO), and their potential applications. Next, we explain the concept of copper oxide and TiO 2 heterojunctions. We summarize and present the photovoltaic characteristics (efficiency, fill factor, circuit current density, and open circuit voltage), thickness, preparation method, and electrode type for solar cells comprising copper oxide and TiO 2. The efficiency of the solar cells ranged from 0.0005% to 1.62%. The thickness of the TiO 2 and cupric oxide layers ranged from 0.06 to 16 µm, and from 0.18 to 1.5 µm, respectively, depending on the fabrication method. Additionally, we review and discuss the available combinations of copper oxide with other materials (Cu 2O with ZnO, CuO with ZnO, and CuO with Si), as well as the effect of the thickness of the copper (i) oxide and copper (ii) oxide on the solar cell performance. Finally, we present aspects to improve the conversion efficiency of heterojunction solar cells with copper oxides combined with TiO 2. This review will be useful for the construction and further development of thin-film solar cells.

SCAPS modelling of ZnO/CdS/CdTe/CuO photovoltaic heterosystem

“…It also helps to increase the efficiency of the solar cell. A promising materials used as an HT-EBL layer in CdTe solar cells are cuprous oxide (Cu2O) and cupric oxide (CuO), which have a large band gap in the range of 2.1 -2.61 eV and ~ 1.51 eV and p-type conductivity [38,39]. CuO and Cu2O are characterized as non-toxic materials that are available, inexpensive and have a high absorption coefficient in the visible range [40].…”

“…In this study a simulation of the back contact layer of thin-film CdTe solar cells using CuO and Cu2O materials were conducted. In particular, it was found that the material of the back contact affects the efficiency of the final cell, , but the obtained data for Cu2O as a back contact material have shown that adding of this layer did not significantly increase the efficiency of the final cell due to the energy difference of the band gap at the transition CdTe/Cu2O [39]. Accordingly, it was decided to add a layer of CuO.…”

Recent Progress in Interconnection Layer for Hybrid Photovoltaic Tandems

“…To offer an efficient ohmic contact assisting carrier recombination, TCOs such as ITO, IZO, and ZTO should feature a conduction band positioned at the valence band of p-type Si with a high work function (or vice versa for the opposite polarity Figure 10. Band alignment diagram of various materials including metal, [215,216] metal compounds, [217][218][219] Si-based passivation layer, [220][221][222][223][224] metal oxides, [138,185,218,[224][225][226][227][228][229] and organic semiconductors and perovskite relative to vacuum level. [230] Fermi level positions are shown as dashed lines.…”

“…Band alignment diagram of various materials including metal, [ 215,216 ] metal compounds, [ 217–219 ] Si‐based passivation layer, [ 220–224 ] metal oxides, [ 138,185,218,224–229 ] and organic semiconductors and perovskite relative to vacuum level. [ 230 ] Fermi level positions are shown as dashed lines.…”

Numerical investigations of the impact of buffer germanium composition and low cost fabrication of Cu2O on AZO/ZnGeO/Cu2O solar cell performances

“…The last improvements concern the optimization of the band alignment of the structure by carefully selecting the buffer layer material. In fact, one limitation of the use of Cu 2 O as the absorber layer is its low electron affinity x = 2.1 eV which creates a conduction band offset with the buffer layer which is typically made of zinc oxide (x = 4.4 eV) [8] or titanium oxide (x = 4.1 eV) [9]. Previous simulations show that the reduction of the electron affinity of the buffer layer to 3.2 eV enhances the efficiency of the device [10].…”