Monolithic All-Perovskite Tandem Solar Cells with Minimized Optical and Energetic Losses

Perovskite-based multijunction solar cells are a potentially cost-effective technology that can help surpass the efficiency limits of single-junction devices. However, both mixed-halide wide-bandgap perovskites and lead-tin narrow-bandgap perovskites suffer from non-radiative recombination due to the formation of bulk traps and interfacial...

Novel coring procedure for Post-Mortem Analysis in CIGS PV Modules

CIGS (CuInGaSe2) solar cells are electronic devices that directly transform sunlight into electricity and fall into the category of thin film photovoltaic devices. Currently, this type of solar cell has reached the record in photovoltaic conversion efficiency of around 23.35%. However, the maturity of a PV technology also requires reliability...

Effects of passivation configuration and emitter surface doping concentration on polarization-type potential-induced degradation in n-type crystalline-silicon photovoltaic modules

System voltages can cause significant degradation in photovoltaic modules. Polarization-type potential-induced degradation (PID) is accompanied by decreases in the short-circuit current density and the open-circuit voltage. The system voltage causes a polarization and surface charge accumulation, increasing the interface recombination. The...

Near-infrared tandem organic photodiodes for future application in artificial retinal implants

Photovoltaic retinal prostheses show great potential to restore sight in patients suffering from degenerative eye diseases by electrical stimulation of the surviving neurons in the retinal network. Herein, organic photodiodes (OPDs) sensitive to near-infrared (NIR) light are evaluated as photovoltaic pixels for future application in retinal...

Low-Temperature Plasma-Assisted Atomic-Layer-Deposited SnO2 as an Electron Transport Layer in Planar Perovskite Solar Cells

In this work, we present an extensive characterization of plasma-assisted atomic-layer-deposited SnO2 layers, with the aim of identifying key material properties of SnO2 to serve as an efficient electron transport layer in perovskite solar cells (PSCs). Electrically resistive SnO2 films are fabricated at 50 °C, while a SnO2 film with a low...

Determination of the temperature dependency of the electrical parameters of CIGS solar cells

Two types of Cu(In,Ga)Se2 (CIGS) solar cells, both designed for implementation in CIGS modules, were subjected to temperatures between 25C and 105C. Simultaneous exposure to AM1.5 illumination allowed the measurement of their electrical parameters at these temperatures. These two types of solar cells, produced with different deposition routes on...

Origin of the dark-current ideality factor in polymer:fullerene bulk heterojunction solar cells

In organic bulk heterojunction solar cells, a deviation of the ideality factor of the dark current from unity is commonly put forward as evidence for the presence of trap-assisted recombination. We demonstrate that the non-ideality of the dark characteristics is determined by deeply trapped carriers in the transport-dominating constituent of the...

Determination of the trap-assisted recombination strength in polymer light emitting diodes

The recombination processes in poly(p -phenylene vinylene) based polymer light-emitting diodes (PLEDs) are investigated. Photogenerated current measurements on PLED device structures reveal that next to the known Langevin recombination also trap-assisted recombination is an important recombination channel in PLEDs, which has not been considered...

Origin of the efficiency enhancement in ferroelectric functionalized organic solar cells

We have investigated the efficiency enhancement of organic solar cells upon incorporation of a thin ferroelectric polymer layer. For non-Ohmic contacts the enhancement is due to an increased open circuit voltage, which is, however, independent of the ferroelectric polarization direction. Ferroelectricity cannot play a role due to depolarization...

A batch process micromachined thermoelectric energy harvester: Fabrication and characterization

Micromachined thermopiles are considered as a cost-effective solution for energy harvesters working at a small temperature difference and weak heat flows typical for, e.g., the human body. They can be used for powering autonomous wireless sensor nodes in a body area network. In this paper, a micromachined thermoelectric energy harvester with 6...

High work function transparent middle electrode for organic tandem solar cells

The use of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) in combination with ZnO as middle electrode in solution-processed organic tandem solar cells requires a pH modification of the PEDOT:PSS dispersion. We demonstrate that this neutralization leads to a reduced work function of PEDOT:PSS, which does not affect the...

Charge transfer dynamics in polymer-fullerene blends for efficient solar cells

Blends of poly(3-hexylthiophene) (P3HT) and the bis-adduct of [6,61-pheuyl-C\61-butyric acid methyl ester (bisPCBM) show enhanced performances in bulk-heterojunction solar cells compared to P3HT:PCBM thin films due to their higher open-circuit voltage. However, it is not clear whether the decrease of the shortcircuit current observed in P3HT...

Corrosion resistance of Zn-Co-Fe alloy coatings on high strength steel

The corrosion properties of electrodeposited zinc-cobalt-iron (Zn-Co-Fe) alloys (up to 40 wt.% Co and 1 wt.% Fe) on steel were studied by using various electrochemical techniques and compared with zinc (Zn) and cadmium (Cd) coatings in 3.5% NaCl solution. It was found that with an increase in Co content in the coating the open circuit potential ...

Electron trapping in higher adduct fullerene-based solar cells

Here, the performance of bulk-heterojunction solar cells based on a series of bisadduct analogues of commonly used derivatives of C60 and C 70, such PCBMs and theirthienyl versions, is investigated. Dueto their higher lowest unoccupied molecular orbital an increase in open-circuit voltage and thus performance is expected. It is shown that the...

Compositional and electric field dependence of the dissociation of charge transfer excitons in alternating polyfluorene copolymer/fullerene blends

The electro-optical properties of thin films of electron donor-acceptor blends of a fluorene copolymer (PF10TBT) and a fullerene derivative (PCBM) were studied. Transmission electron microscopy shows that in these films nanocrystalline PCBM clusters are formed at high PCBM content. For all concentrations, a charge transfer (CT) transition is...

Photoinduced charge and energy transfer in dye-doped conjugated polymers

Conjugated polymer-molecular dye blends of MDMO-PPV (poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene]) and PF1CVTP (poly[9,9-dioctylfluorene-2,7-diyl-alt-2,5-bis(2-thienyl-1-cyanovinyl)-1-(3′,7′-dimethyloctyloxy)-4-methoxybenzene-5″,5″-diyl]) with three dipyrrometheneboron difluoride (bodipy) dyes were studied by (time-resolved)...