Combinatorial solar cell libraries for the investigation of different metal back contacts for TiO₂–Cu₂O hetero-junction solar cells

Abstract

Here we present a comprehensive investigation of TiO2-Cu2O hetero-junction solar cells with different back contacts (Au, ITO, Cu or Ag). Combinatorial hetero-junction libraries consisting of a linear TiO2 thickness gradient produced by spray pyrolysis and a bell shaped Cu2O profile synthesized by pulsed laser deposition were chosen to investigate the impact of the two metal oxide layer thicknesses. The back contacts were deposited as round patches onto a grid of 13 × 13 points, 169 contacts for each contact material, forming a library containing 4 × 13 × 13 = 676 back contacts. Each back contact represented a solar cell with an individual TiO2 and Cu2O thickness. I-V measurements show that all four materials provide an ohmic contact and that the open circuit voltage of ∼300 mV is rather independent of both layer thicknesses and contact material. The size of the Cu2O crystals drastically decreases with distance from the center of deposition, which leads to a drastic increase of series resistance when the crystal size is <50 nm.

Data Mining and Machine Learning Tools for Combinatorial Material Science of All‐Oxide Photovoltaic Cells

“…Most of these requirements are met by metal oxides (MOs) which are emerging as new materials for the production of solar cells. Yet before all metal oxide photovoltaic cells enjoy widespread usage, they still need to demonstrate a substantial increase in their sun light to electricity conversion efficiency 2. This in turn requires the development of new MOs.…”

“…Briefly, their basic assembly includes (see Figure 1): (1) A transparent conducting oxide (TCO) coated on a glass, typically in the form of fluorine doped tin oxide (FTO); (2) Window layer, which is a wide band‐gap n‐Type semiconductor; (3) Light absorbing layer (absorber); (4) Metal back contact; (5) Metal frame (front contact) soldered directly onto the TCO. This basic design could be transformed into a solar cells library by using combinatorial material synthesis for the window and absorber layers 2,4,6…”

Thermal decomposition approach for the synthesis of CdS–TiO2 nanocomposites and their catalytic activity towards degradation of rhodamine B and reduction of Cr(VI)

“…Among the modified TiO 2 photocatalysts, coupling of a narrow band gap semiconductor with TiO 2 to form nanocomposites is considered as one of the most promising ways for harvesting the sunlight with enhancement of quantum yield [13]. Some of the semiconductors with narrow band gap that have been coupled with TiO 2 are PbS [14], CdTe [15], CdSe [16], ZnFe 2 O 4 [17], Cu 2 O [18] and CdS [19][20][21].…”

Application of Materials Informatics Tools to the Analysis of Combinatorial Libraries of All Metal-Oxides Photovoltaic Cells

“…Such cells are reasonably cheap to manufacture due to the abundance of their constituting elements, are environmentally friendly and are stable over time. Yet, their performances in terms of their ability to convert sunlight into electricity need to be improved [6]. Such improvements require the development of new MOs which could benefit from combining combinatorial materials science for producing solar cells libraries with machine learning approaches to analyze the resulting libraries and direct synthesis efforts.…”