Maria Méndez

• PhD
• PostDoc Position at Institute of Chemical Research of Catalonia

Four different carbazole‐based self‐assembled molecules with different terminal groups have been designed and synthesised as hole‐selective contacts for inverted perovskite solar cells to investigate their interfacial interactions and, consequently, the performance of the devices. Using the carbazole core as a reference, we compared the effect of t...

Correction for ‘Influence of the carbazole moiety in self-assembling molecules as selective contacts in perovskite solar cells: interfacial charge transfer kinetics and solar-to-energy efficiency effects’ by Dora A. González et al. , Nanoscale Adv. , 2023, 5 , 6542–6547, https://doi.org/10.1039/d3na00811h.

The use of self-assembled molecules (SAMs) as hole transport materials (HTMs) in p–i–n perovskite solar cells (iPSCs) has triggered widespread research due to their relatively easy synthetic methods, suitable energy level alignment with the perovskite material and the suppression of chemical defects. Herein, three new SAMs have been designed and sy...

A ternary strategy has been demonstrated as being an effective method to improve the power conversion efficiency (PCE); however, general rules for materials selection are not fully comprehended. Herein, nonfullerene acceptor ITIC-M and fullerene acceptor PC70BM possessing higher lowest unoccupied molecular orbital (LUMO) and good miscibility with n...

Good selective contacts are necessary for solar cells that are efficient and have long-term stability. Since 1998, with the advent of solid-state dye sensitized solar cells (DSSC), Spiro-OMeTAD has become the reference hole-transporting material. Yet, for efficient solar cells Spiro-OMeTAD must be partially oxidized with chemical dopants, which com...

Finding an effective approach to suppress trap formation is a potential route for enhancing the performance of nonfullerene organic photovoltaic (NF‐OPVs) devices. Here, an extraordinary short‐circuit current density (JSC) value of 32.65 mA cm‐2 is achieved, higher than the state‐of‐the art NF‐OPVs reported, reaching a high power conversion efficie...

The performance and industrial visibility of organic solar cells (OSCs) are greatly impacted by the functionality and stability of the interfacial layers. Many reported interface materials exhibited limitations in their fabrication temperature along with the operational stability toward the industrial up-scalability. In this work, a systematic anal...

In this work, we have used TiO2 and SnO2 layers as electron selective contact (ESC) in n-i-p perovskite solar cells configuration. To study and compare the ion migration kinetics of these ESC, CsFAMAPbIBr and MAPbI3-based devices were fabricated and characterised in fresh (1 day) and aged (28 days) conditions. Depending on the ESC and perovskite co...

In this work, we present our results on the influence of post-deposition treatments on the morphology and optical properties of photoactive films made of small molecules and their subsequent effect on the performance of photovoltaic (PV) devices. We have chosen DPP(TBFu)2:PC61BM as a benchmark model system and compared a novel joule-heating anneali...

The device operational lifetime and the understanding of the degradation pathways are critical steps for inverted organic solar cells (iOSCs) to enter the energy market. In this work, a combined study of impedance spectroscopy (IS) and photovoltage/photocurrent transient (TPV/TPC) techniques was employed to analyze the degradation of PTB7-Th:PC70BM...

Previous studies have revealed that for some perovskite compositions, power conversion efficiencies (PCEs) improved after storing the devices in different ambient conditions. With the aim of better understanding such improvements, we focus our attention on the carrier/ionic dynamic kinetics of fresh and aged PSCs with different perovskite compositi...

Current perovskite solar cell efficiency is close to silicon's record values. Yet, the roadblock for industrialization of this technology is its stability. The stability of the solar cell not only depends on the stability of the perovskite material itself but also notably on its contact layers and their interface with the perovskite, which plays a...

Our work analyses for the first time the kinetics of perovskite/organic photovoltaic (OPV) interface with different perovskite I/Br ratios (MAPbI3-xBrx, x=0, 1, 2, and 3) and PM6:Y6 as bulk heterojunction blend. The aim was to study in depth the combination of wide band gap perovskite material ‒that allows large open-circuit voltage‒ and the PM6:Y6...

To reduce the amount of conducting additives generally required for polynitroxide‐based electrodes, a stable radical (TEMPO) is combined with a conductive copolymer backbone consisting of 2,7‐bisthiophene carbazole (2,7‐BTC), which is characterized by a high intrinsic electronic conductivity. This work deals with the synthesis of this new polymer f...

Three hole transport materials (HTMs) based on a substituted triphenylamine moiety have been synthesized and successfully employed in triple‐cation mixed‐halide PSCs, reaching efficiencies of 19.4 %. The efficiencies, comparable to those obtained using spiro‐OMeTAD, point them out as promising candidates for easily attainable and cost‐effective alt...

Drei Lochtransportmaterialien (HTMs) basierend auf einem substituierten Triphenylaminbaustein wurden in Perowskit-Solarzellen eingesetzt, die Effizienzen von 19.4 % erreichten. Die HTMs haben sehr ähnliche chemische und physikalische Eigenschaften, zeigen aber deutlich verschiedene Ladungsträgerrekombinationskinetiken. Abstract Three hole transpor...

Previous reports have observed a direct relationship between the polymer poly(3-hexylthiophene) molecular weight (MW) and the perovskite solar cell (PSC) efficiency. Herein, we analyse how the differences in MW and the differences in energetic disorder influence the interfacial carrier losses in the PSCs under operation conditions and explain the o...

We describe in this work how the use of photo-induced charge extraction (PICE) technique can be useful to study and understand the relationship between perovskite composition, ion migration processes and solar cell performance. Our results show that varying the organic cation and halide composition in perovskite crystals have an effect over the cha...

We investigate the dual use of tris(8-hydroxyquinolinato)aluminium, known as Alq3, as selective contact for electrons and, moreover, as fluorescence emitting layer to increase the photocurrent of perovskite solar cells.

Mixed halide hybrid perovskites CH3NH3PbI3-xClx (MAPICl) show higher charge carrier diffusion lengths, improved solar cell characteristics and enhanced stability as compared to their single halide counterparts CH3NH3PbI3 (MAPI). This is surprising in view of the fact that the actually observed Cl content is very low (x < 0.1) as the incorporation o...

Several lanthanum hydroxides (28–146 m2/g) were prepared by different procedures involving precipitation and hydrothermal methods by conventional heating or with microwaves. The use of ultrasounds during precipitation led to the formation of additional crystalline phases whereas the aging treatment with microwaves decreased the temperature needed t...

http://hdl.handle.net/10803/101521

The charge transfer state (CTS) band of the Eu3+:La2O3 nanocrystals were studied in detail in order to understand the shift of the maximum of this band. Eu3+:La2O3 nanoparticles present a broad CTS band. However, the maximum is peaking below 300 nm, far below the limit of the solar spectrum arriving to the surface of the Earth and it makes difficul...

Europium-doped La(2)O(3) nanocrystalline powders with sizes in the range of 50-200 nm have been obtained by the modified sol-gel Pechini method. These nanocrystals have been deagglomerated using sonication for 3 h and have been dispersed into a semiconductor P3HT polymeric matrix. We studied and analysed the spectroscopic properties of the trivalen...

Europium-doped La2O3 nanocrystalline powders with sizes ranging from 4nm to 300nm have been obtained by the modified Pechini, hydrothermal with conventional furnace, hydrothermal with microwave furnace, and precipitation with ultrasonic bath methods. X-ray diffraction techniques were used to study the evolution of the prepared gels towards the desi...

Europium doped La2O3 nanocrystalline powders with sizes in the range of 50-200 nm have been obtained by the modified sol-gel Pechini method. These nanocrystals have been deagglomerated using sonication for 3 h and have been dispersed into a semiconductor P3HT polymeric matrix. X-ray diffraction (XRD) was used to study the evolution of the desired c...