The use of chlorinated solvents such as chlorobenzene for PCBM processing in perovskite solar cells (PSCs) raises environmental and occupational safety concerns. Here, anisole is proposed as a green solvent alternative for PCBM deposition in p-i-n PSCs and flexible minimodules. By optimizing the ink concentration, uniform PCBM layers were obtained with an optimal thickness of 38 nm and a low surface roughness of 4.88 nm. This resulted in reduced series resistance (R1 = 12.48 Ω vs. 13.26 Ω for CB) and a lower ideality factor (1.34 vs. 1.41), enabling efficient interfacial charge extraction and power conversion efficiencies up to 15.98%. Devices retained 95% of their initial PCE after 1100 h under ISOS-D1I and showed improved thermal stability (T80 = 96 h), confirming that solvent substitution does not introduce additional degradation pathways. Furthermore, anisole-based inks were compatible with slot-die coating in roll-to-roll processing, achieving 7.04% efficiency in flexible devices. These results highlight anisole as a safer and greener solvent alternative to chlorobenzene, combining high performance, enhanced stability, and scalability, making it a promising candidate for more sustainable perovskite solar cell manufacturing.

Room temperature processing of flexible electronics has become of great interest, as it allows for simpler and cheaper methodologies for high throughput manufacturing of printed electronics. This study focuses on the development and characterization of carbon-based conductive pastes made from a combination of graphite (G) and carbon black (CB), in a polymethyl methacrylate (PMMA) polymer matrix. Raw materials were characterized by Raman Spectroscopy, FTIR, SEM and TEM, showing the structural properties, morphologies and particles size which influenced the characteristics of the pastes. By varying the ratios of G/CB (1 to 4), carbon filler content (11.6–20%), and polymer content (1.5–7%), 48 different formulations were fabricated and further analyzed to determine their electrical conductivity as films. This process identified the optimal formulation for each G/CB ratio. Pastes with higher relative graphite content (G/CB ratios of 3 and 4) yielded the lowest resistivities (as low as 0.078 Ω cm) attributed to the effective formation of conductive networks between G and CB. Best-performing pastes were further characterized by sheet resistance, viscosity, adhesion, and scanning electron microscopy (SEM) analysis to understand the microstructure of the films. Flexible electrodes fabricated on PET substrates withstood 6000 bending cycles, thermal stress at 70 °C, and immersion in water, maintaining electrical conductivity. These results have significant implications for the future development of carbon-based conductive materials for room-temperature applications in flexible and printed electronics.

Perovskite solar technology stands on three different pillars: efficiency, stability, and processability. Focusing on processability, the field demands the achievement of optoelectronic grade active layers with high uniformity fabricated by industry‐compatible methods. Herein, the design and implementation of an air knife on a blade coating deposition system, which allows controlling the evaporation rate of the solvents improving the crystallization and uniformity of perovskite films in a p–i–n device are reported. The effect of doctor blade operational parameters is studied using image analysis combined with a machine learning method to identify the most relevant processing variables leading to a uniform perovskite layer with optimal thickness. After implementing the air knife system and finding the best processing conditions, a special perovskite solar minimodule enabling the evaluation of single inner subcells is fabricated. These perovskite subcells reach an average efficiency of 10.1% and remarkably all the subcells deviate less than 20% from this value over a large‐area substrate. These results demonstrate the promising potential of this fabrication method for low cost and high deposition rate photovoltaic devices, which is on the path to mass production.

Electrification using renewable energy sources represents a clear path toward solving the current global energy crisis. In Colombia, this challenge also involves the diversification of the electrical energy sources to overcome the historical dependence on hydropower. In this context, green hydrogen represents a key energy carrier enabling the storage of renewable energy as well as directly powering industrial and transportation sectors. This work explores the realistic potential of the main renewable energy sources, including solar photovoltaics (8172 GW), hydropower (56 GW), wind (68 GW), and biomass (14 GW). In addition, a case study from abroad is presented, demonstrating the feasibility of using each type of renewable energy to generate green hydrogen in the country. At the end, an analysis of the most likely regions in the country and paths to deploy green hydrogen projects are presented, favoring hydropower in the short term and solar in the long run. By 2050, this energy potential will enable reaching a levelized cost of hydrogen (LCOH) of 1.7, 1.5, 3.1 and 1.4 USD/kg-H2 for solar photovoltaic, wind, hydropower and biomass, respectively.

Large‐scale manufacturing of perovskite solar cells (PSCs) requires the deposition of homogeneous and defect‐free perovskite films on large‐area substrates. Up to now, the knowledge developed for industrial slot‐die processing has not been fully transferred to the perovskite photovoltaic community. Here, the deposition of uniform perovskite layers by slot‐die coating (SDC). Computer fluid dynamics (CFD) simulations, experimental validation, and calculation of industrial uniformity parameters are demonstrated, which enabled to establish processing conditions for SDC of perovskite ink. This approach allowed for obtaining stable cross‐web flow in the slot‐die head resulting in the formation of a stable coating bead yielding uniform perovskite films. The best processing parameters are used for the fabrication of slot‐die‐coated PSCs, which showed a more homogeneous spatial distribution of photovoltaic parameters compared to their spin‐coated counterparts. Better reproducibility observed in device performance is a step forward toward the commercialization of perovskite photovoltaic technology. For the first time, the industrial approach used for the optimization of slot‐die coating is applied for the processing of perovskite inks that have special conditions such as low viscosity and in situ crystallization on the substrate.

Commercialization of perovskite solar technology depends on reaching a stable functioning of the devices. In this regard, both intrinsic (chemistry phenomena of the different device layers) and extrinsic factors (environmental) need to be considered. In this chapter, we report the state of the art of encapsulation techniques against extrinsic degradation mechanisms. Our analysis includes the most common encapsulation structures, materials employed and their by-products, standard methods to test the stability of the devices (accelerated testing, outdoor and degradation monitoring), and security requirements to prevent the health/environmental hazard of lead leakage.

This article presents details of the design, construction and operation of a low cost reactor for growth of thin films of Chalcogenide Materials used for Photovoltaic applications. This reactor allows growing any type of chalcogenide compound by chalcogenisation of their metal precursors. However its performance was tested by depositing CuSbS2 films by chalcogenisation of metal precursors sequentially deposited by evaporation. The sulfurization process includes soft annealing of the Sb/Cu stacked precursor in a controlled atmosphere mixture of argon and hydrogen gas (95% Ar and 5% H2) followed by heating in the presence of elemental sulfur, using a tubular furnace heated with infrared lamps. Chalcogenisation process is carried out by controlling the heating rate of the furnace with the help of algorithms developed using LabVIEW programming environment. Through a study of deposition parameters that included the variables, furnace heating rate, final annealing target temperature and annealing time, conditions were found to grow single-phase CuSbS2 films with good structural, optical and morphological properties. This indicates that the CuSbS2 films prepared by means the chalcogenisation routine developed in this work, could be used later as an absorbent layer in solar cells.

Micro structural and optical properties of ZnO and TiO2 films prepared by spray pyrolysis were studied by XRD (X-ray diffraction) analysis and measurements of transmittance and Urbach Energy. The influence of preparation conditions on the micro structural properties of ZnO and TiO2 films was investigated throug the evaluation of the X-ray peak broadening. The Williamson Hall (W-H) analysis and size strain plot method were used to study the individual contributions of crystallite sizes and lattice strain on the peak broadening. The physical parameters such as strain, stress and energy density values were calculated for all the reflection peaks of XRD corresponding to both type of samples from the modified form of the W-H plot assuming a uniform deformation model (UDM), uniform stress deformation model (USDM) and uniform deformation energy density model (UDEDM). It was found that the particle mean size of the ZnO and TiO2 films estimated from the W-H method agree quite good with AFM results. Further, information regarding the influence of preparation conditions on the formation of structural defects was achieved through Urbach energy measurements.

This work reports results of a study carried out to improve the optical, electrical and microstructural properties of Cu2ZnSnS4 (CZTS) films grown by spray pyrolysis in a one-step process using a precursor solution prepared dissolving thiourea and salts of Cu, Sn and Zn in a solvent constituted by a mixture of dimethyl sulfoxide (DMSO) and acetone. The improvement of the properties of the CZTS films was achieved through a parameters study performed by using an experimental design 2(3) face centered central composite design (FCCCD). The study revealed that substrate temperature (T-s), carrier gas pressure (P-g), spray pulse time (t(sp)) as well as their interaction are the parameters that most critically affect the above mentioned properties. Special emphasis was done on studying the influence of these parameters on the micro structural properties of the CZTS films using the XRD peak broadening method and Williamson-Hall equations, assuming the models UDM (uniform deformation model), USDM (uniform stress deformation model) and UDEDM (uniform deformation energy density model). Further, information regarding the influence of preparation conditions on the formation of structural defects was achieved through Urbach energy measurements.

Este trabajo presenta detalles del diseño e implementación de un sistema de medición de voltaje Hall en dependencia de la temperatura, desarrollado usando el concepto de Instrumentación Virtual. Para tal efecto se usó hardware de la National Instruments y el paquete LabVIEW como software. El sistema es controlado a través de un instrumento virtual (IV) que incluye facilidades para realizar control PID de temperatura de la muestra en el rango 80 K - 700 K, medición de voltaje Hall (VH) usando el método de cuatro contactos y visualización en tiempo real de la curva de VH vs T. El sistema fue probado realizando medidas de voltaje Hall vs T a películas delgadas de CuInS2 usadas como capa absorbente en celdas solares, con el propósito de obtener información de sus propiedades de transporte eléctrico.

Results regarding optical and structural properties of Cu2ZnSnS4 (CZTS) thin films prepared by co-evaporation using a novel procedure are compared with those obtained with CZTS films grown using a solution based route. The lattice strain ε and crystallite size D of CZTS films prepared by co-evaporation and by spray pyrolysis were estimated through X-ray diffraction (XRD) measurements using Williamson-Hall-isotropic strain model. The results of estimated average crystallite size of CZTS films by Scherrer and Williamson-Hall plot methods were compared with AFM (atomic force microscopy) measurements. It was found that the average crystallite size measured by Williamson-Hall plot methods agree quite well with AFM results. Further, information regarding the influence of preparation method on both, crystalline phases and the formation of structural defects was achieved through Raman and Urbach energy measurements.

iii) Electronic system implemented using virtual instrumentation with facilities to control the sample temperature through a PID algorithm and to perform functions of control, acquisition, processing and monitoring of data. The equipment also allows to realize photocurrent measurements at different pressures, which are controlled through an electronic mass flow controller connected to a cylinder with compressed air, keeping the vacuum system in operation.

This work describes a route to grow single phase Cu 2 ZnSnS 4 (CZTS) thin films in one step process using spray pyrolysis technique, followed by annealing at 773K in nitrogen-atmosphere. The precursor solution was prepared dissolving metallic salts and thiourea in dimethyl sulfoxide (DMSO). The effect of film thickness and annealing temperature on the phases formed in the CZTS films, as well as its optical and structural properties have been studied through transmittance, Urbach energy (Eu), X-ray diffraction (XRD) and Raman spectroscopy measurements. Raman scattering analysis allowed identifying symmetric vibrational modes associated to different phases. It was found that single phase CZTS films with tetragonal structure are formed when thin films of thickness greater than or equal to 1 μm are subjected to annealing at 773K during 30 min, in a chamber maintained at nitrogen partial pressure of 20 mBar. This type of CZTS films have low Urbach energy, indicating that are characterized by a low density of structural defects.

This work describes a novel system implemented to grow ZnO thin films by plasma assisted reactive evaporation with adequate properties to be used in the fabrication of photovoltaic devices with different architectures. The innovative aspect includes both an improved design of the reactor used to activate the chemical reaction that leads to the formation of the ZnO compound as an electronic system developed using the virtual instrumentation concept. ZnO thin films with excellent opto-electrical properties were prepared in a reproducible way, controlling the deposition system through a virtual instrument (VI) with facilities to control the amount of evaporated zinc involved in the process that gives rise to the formation of ZnO, by means of the incorporation of PID (proportional integral differential) and PWM (pulse width modulation) control algorithms. The effectiveness and reliability of the developed system was verified by obtaining with good reproducibility thin films of n+-ZnO and i-ZnO grown sequentially in situ with thicknesses and resistivities suitable for use as window layers in chalcopyrite based thin film solar cells.