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...

Monolithic Two-Terminal Perovskite/CIS Tandem Solar Cells with Efficiency Approaching 25%

Monolithic two-terminal (2T) perovskite/CuInSe2 (CIS) tandem solar cells (TSCs) combine the promise of an efficient tandem photovoltaic (PV) technology with the simplicity of an all-thin-film device architecture that is compatible with flexible and lightweight PV. In this work, we present the first-ever 2T perovskite/CIS TSC with a power...

Identification of the Origin of Ultralow Dark Currents in Organic Photodiodes

Organic bulk heterojunction photodiodes (OPDs) attract attention for sensing and imaging. Their detectivity is typically limited by a substantial reverse bias dark current density (Jd). Recently, using thermal admittance or spectral photocurrent measurements, Jd has been attributed to thermal charge generation mediated by mid-gap states. Here,...

Strong Quantum Confinement Effects and Chiral Excitons in Bio-Inspired ZnO-Amino Acid Cocrystals

Elucidating the underlying principles behind band gap engineering is paramount for the successful implementation of semiconductors in photonic and optoelectronic devices. Recently it has been shown that the band gap of a wide and direct band gap semiconductor, such as ZnO, can be modified upon cocrystallization with amino acids, with the role of...

Benchmarking photoactive thin-film materials using a laser-induced steady-state photocarrier grating

In this study, we assess the charge carrier diffusive transport quality of traditional and emerging thin-film photoactive absorber materials used for photovoltaic applications. We use a steady-state photocarrier grating technique, which has so far been predominantly used for amorphous silicon-based materials, to obtain ambipolar diffusion...

Role of balanced charge carrier transport in low band gap polymer: Fullerene bulk heterojunction solar cells

Lowering of the optical band gap of conjugated polymers in bulk heterojunction solar cells not only leads to an increased absorption but also to an increase of the optimal active layer thickness due to interference effects at longer wavelengths. The increased carrier densities due to the enhanced absorption and thicker active layers make low...

Enhanced dissociation of charge-transfer states in narrow band gap polymer:fullerene solar cells processed with 1,8-octanedithiol

The improved photovoltaic performance of narrow band gap polymer:fullerene solar cells processed from solutions containing small amounts of 1,8-octanedithiol is analyzed by modeling of the experimental photocurrent. In contrast to devices that are spin coated from pristine chlorobenzene, these cells do not produce a recombination-limited...

EBG enhanced feeds for the improvement of the aperture efficiency of reflector antennas

We describe the use of electromagnetic bandgap (EBG) super-layers to improve the shape of reflectors illumination function. Following an investigation of the leaky wave pole singularities of the EBG Green's function, the shape of the radiation patterns of small apertures in ground planes are optimized. The maximization of the reflector aperture...

On the use of planar EBGs in One Dimensional (1D) scanning printed arrays

In a companion paper [1] presented in this same conference, the use of Planar Circularly Symmetric (PCS) Electromagnetic Band-Gap (EBG) structures for optimizing the performances of single antenna elements is discussed. A completely planar antenna with 20% of bandwidth which does not suffer from surface wave effects is presented. The key...