Direct fabrication of arrays of Cu(In,Ga)Se2 micro solar cells by sputtering for micro-concentrator photovoltaics

in Materials & Design (2023)

Inkjet-printed indium sulfide buffer layer for Cu(In,Ga)(S,Se)2 thin film solar cells

in Thin Solid Films (2022)

We report an environmentally friendly inkjet-printed indium sulfide (In2S3) buffer layer using benign chemistry and processing conditions. A pre-synthesized indium-thiourea compound is dissolved in a ... [more ▼]

We report an environmentally friendly inkjet-printed indium sulfide (In2S3) buffer layer using benign chemistry and processing conditions. A pre-synthesized indium-thiourea compound is dissolved in a mixture of water and ethanol, inkjet printed on a Cu(In,Ga)(S,Se)2 absorber and annealed in air. The buffer layer shows a β-In2S3 structure with few organic impurities and band gap in the range of 2.3 eV. An ultraviolet ozone treatment applied to the surface of the absorber prior to inkjet printing of the precursor is used to improve the wettability of the ink and therefore the surface coverage of the buffer on the absorber layer. The device with a fully covering In2S3 layer shows better open circuit voltage and fill factor than the device with a partially covering In2S3 layer. The best In2S3 device showed a light to electric power conversion efficiency similar to the reference cadmium sulfide buffer layer device. Good wettability conditions are therefore essential for higher efficiency solar cells when the buffer layer is inkjet-printed. [less ▲]

Post-deposition annealing and interfacial atomic layer deposition buffer layers of Sb2Se3/CdS stacks for reduced interface recombination and increased open-circuit voltages

in Progress in Photovoltaics (2022)

Waste- and Cd-Free Inkjet-Printed Zn(O,S) Buffer for Cu(In,Ga)(S,Se)2 Thin-Film Solar Cells

in ACS Applied Materials and Interfaces (2021), 13

Solution-based synthesis of kesterite thin film semiconductors

in Journal of Physics : Energy (2020)

Atmospheric-Pressure Synthesis of Atomically Smooth, Conformal, and Ultrathin Low‑k Polymer Insulating Layers by Plasma-Initiated and Ultrathin Low‑k Polymer Insulating Layers by Plasma-Initiated

in ACS Applied Polymer Materials (2020)

Micro‐sized thin‐film solar cells via area‐selective electrochemical deposition for concentrator photovoltaics application

in scientific reports (2020)

Area-selective electrodeposition of micro islands for CuInSe2-based photovoltaics

in Results in Physics (2019), 12

Synthesis, theoretical and experimental characterisation of thin film Cu2Sn1-xGexS3 ternary alloys (x = 0 to 1): Homogeneous intermixing of Sn and Ge

in Acta Materialia (2018), 151

Cu2Sn1-xGexS3 is a p-type semiconductor alloy currently investigated for use as an absorber layer in thin film solar cells. The aim of this study is to investigate the properties of this alloy in thin ... [more ▼]

Cu2Sn1-xGexS3 is a p-type semiconductor alloy currently investigated for use as an absorber layer in thin film solar cells. The aim of this study is to investigate the properties of this alloy in thin film form in order to establish relationships between group IV composition and structural, vibrational and opto-electronic properties. Seven single phase Cu2Sn1-xGexS3 films are prepared from x ¼ 0 to 1, showing a uniform distribution of Ge and Sn laterally and in depth. The films all show a monoclinic crystal structure. The lattice parameters are extracted using Le Bail refinement and show a linear decrease with increasing Ge content. Using density-functional theory with hybrid functionals, we calculate the Raman active phonon frequencies of Cu2SnS3 and Cu2GeS3. For the alloyed compounds, we use a virtual atom approximation. The shift of the main Raman peak from x ¼ 0 to x ¼ 1 can be explained as being half due to the change in atomic masses and half being due to the different bond strength. The bandgaps of the alloys are extracted from photoluminescence measurements and increase linearly from about 0.90 to 1.56 eV with increasing Ge. The net acceptor density of all films is around 1018 cm 3. These analyses have established that the alloy forms a solid solution over the entire composition range meaning that intentional band gap grading should be possible for future absorber layers. The linear variation of the unit cell parameters and the band gap with group IV content allows composition determination by scattering or optical measurements. Further research is required to reduce the doping density by two orders of magnitude in order to improve the current collection within a solar cell device structure. [less ▲]

Nanometre-scale optical property fluctuations in Cu2ZnSnS4 revealed by low temperature cathodoluminescence

in Solar Energy Materials and Solar Cells (2018), 174