Publications by Sandy Sanchez Alonso

Unlocking high-performance photocapacitors for edge computing in low-light environments

Driving continuous, low-power artificial intelligence (AI) in the Internet of Things (IoT) requires reliable energy harvesting and storage under indoor or low-light conditions, where batteries face constraints such as finite lifetimes and increased environ ...

2025

TEMPO bulk passivation boosts the performance and operational stability of rapid-annealed FAPI perovskite solar cells

Michael Graetzel, Kevin Sivula, Sandy Sanchez Alonso, Felix Thomas Eickemeyer, Lukas Pfeifer

In this work, we present a high-performance, stable formamidinium lead iodide (FAPI) perovskite solar cell (PSC) achieved through the use of 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) bulk passivation and rapid photonic annealing. Utilizing flash infrared ...

2025

Photonic Processing of MAPbI(3) Films by Flash Annealing and Rapid Growth for High-Performance Perovskite Solar Cells (vol 6, 2200641, 2022)

Sandy Sanchez Alonso

2023

Thermally controlled growth of photoactive FAPbI(3) films for highly stable perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Cyril Cayron, Sandy Sanchez Alonso, Pascal Alexander Schouwink, Felix Thomas Eickemeyer

We employ flash infrared annealing to investigate the phase transition of formamidinium lead triiodide (FAPbI(3)) thin films for their solar cell applications. Measuring the enthalpy changes of the FAPbI(3) composition at different heating rates allows us ...

ROYAL SOC CHEMISTRY2022

Photonic Processing of MAPbI(3) Films by Flash Annealing and Rapid Growth for High-Performance Perovskite Solar Cells

Sandy Sanchez Alonso

Defects in polycrystalline halide perovskite films can cause a decrease of the solar cell photoconversion efficiency and stability. The perovskite film enhanced during crystal growth by controlling the processing method can alleviate defects and the relate ...

2022

A universal co-solvent dilution strategy enables facile and cost-effective fabrication of perovskite photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Ulf Anders Hagfeldt, Sandy Sanchez Alonso, Narges Yaghoobi Nia, Linfeng Pan, Paramvir Ahlawat, Viacheslav Bolnykh, Dan Ren, Masaud Hassan S Almalki, Hong Zhang, Anurag Krishna, Tzu-Sen Su

Cost management and toxic waste generation are two key issues that must be addressed before the commercialization of perovskite optoelectronic devices. We report a ground-breaking strategy for eco-friendly and cost-effective fabrication of highly efficient ...

Nature Research2022

Flash Infrared Annealing for Perovskite Solar Cell Processing

Ulf Anders Hagfeldt, Sandy Sanchez Alonso

Organic-inorganic perovskites have an impressive potential for the design of next generation solar cells and are currently considered for upscaling and commercialization. Currently, perovskite solar cells rely on spin-coating which is neither practical for ...

JOURNAL OF VISUALIZED EXPERIMENTS2021

Nanoscale interfacial engineering enables highly stable and efficient perovskite photovoltaics

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mounir Driss Mensi, Ursula Röthlisberger, Ulf Anders Hagfeldt, Sandy Sanchez Alonso, Mathias Dankl, Hong Zhang, Anurag Krishna, Olivier Ouellette

We present a facile molecular-level interface engineering strategy to augment the long-term operational and thermal stability of perovskite solar cells (PSCs) by tailoring the interface between the perovskite and hole transporting layer (HTL) with a multif ...

2021

Thermodynamic stability screening of IR-photonic processed multication halide perovskite thin films

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Sandy Sanchez Alonso, Natalie Flores Diaz, Pascal Alexander Schouwink, Brian Irving Carlsen

We report a material screening study for phase transitions of multication hybrid halide perovskite films. Two hundred sixty-six films processed with flash infrared annealing were optically and structurally characterized. This data was compiled into a datab ...

Royal Society of Chemistry2021

Rapid hybrid perovskite film crystallization from solution

Nikolaos Vlachopoulos, Ulf Anders Hagfeldt, Sandy Sanchez Alonso, Lukas Pfeifer

The use of a solution process to grow perovskite thin films allows to extend the material processability. It is known that the physicochemical properties of the perovskite material can be tuned by altering the solution precursors as well as by controlling ...

Royal Society of Chemistry2021

Highly efficient and rapid manufactured perovskite solar cells via Flash InfraRed Annealing

Ulf Anders Hagfeldt, Sandy Sanchez Alonso, Michael Saliba

This work unveils how to quickly manufacture highly efficient and stable perovskite solar cells (PSCs) using the Flash InfraRed Annealing (FIRA) method. With FIRA, the titanium oxide mesoscopic layer can be synthesized in only 10 min, and the synthesis of ...

2020

Revealing the Perovskite Film Formation Using the Gas Quenching Method by In Situ GIWAXS: Morphology, Properties, and Device Performance

Ulf Anders Hagfeldt, Sandy Sanchez Alonso, Rodrigo Szostak

The optoelectronic properties, morphology, and consequently the performance of metal halide perovskite solar cells are directly related to the crystalline phases and intermediates formed during film preparation. The gas quenching method is compatible with ...

2020

Ultrathin polymeric films for interfacial passivation in wide band-gap perovskite solar cells

Sandy Sanchez Alonso

Wide band-gap perovskite solar cells have the potential for a relatively high output voltage and resilience in a degradation-inducing environment. Investigating the reasons why high voltages with adequate output power have not been realized yet is an under ...

NATURE RESEARCH2020

Flash Infrared Pulse Time Control of Perovskite Crystal Nucleation and Growth from Solution

Sandy Sanchez Alonso, Michael Saliba

Flash infrared annealing (FIRA) of perovskite films enables manufacturing compact perovskite layers for photovoltaic devices. Here, a variable infrared pulse length to control crystal nucleation and growth in perovskite films is investigated. By varying th ...

AMER CHEMICAL SOC2020

Crystal Orientation and Grain Size: Do They Determine Optoelectronic Properties of MAPbI(3) Perovskite?

Ulf Anders Hagfeldt, Sandy Sanchez Alonso, Michael Saliba

Growing large, oriented grains of perovskite often leads to efficient devices, but it is unclear if properties of the grains are responsible for the efficiency. Domains observed in SEM are commonly misidentified with crystallographic grains, but SEM images ...

2019

Flash infrared annealing as a cost-effective and low environmental impact processing method for planar perovskite solar cells

Sandy Sanchez Alonso, Michael Saliba

For successful commercialization of perovskite solar cells, straightforward solutions in terms of environmental impact and economic feasibility are still required. Flash Infrared Annealing (FIRA) is a rapid method to fabricate perovskite solar cells with e ...

2019