Search

The conversion efficiency of organic solar cells suffers from their low open-circuit voltages. Here, the authors expose a link between electron-vibrations coupling and non-radiative recombinations, derive a new limit for the efficiency of organic solar cells, and redefine their optimal optical gap.

Traditional methods for tuning the dimensions of organic electronic device structures often rely on cumbersome processes with limited resolution. Here, the authors report ultraviolet irradiation in ambient conditions for tuning structural parameters for organic small molecule hole transport layers.

Organic permeable base transistors featuring a porous aluminium electrode within the semiconductor channel enable high photo-gain and charge storage simultaneously. The transistors achieve retention times beyond 10.000 s while operating at less than 2 V with responsivity as high as 10⁹ A W⁻¹.

Charge-transfer states with comparable recombination and charge-splitting rates are shown to be a key ingredient for donor–acceptor organic blends that perform well in both light-emitting and photovoltaic applications.

Organic thin-film lasers offer compact, low-cost light sources for applications like sensing and optical memory. Here, authors fabricated sub-wavelength gratings using a femtosecond laser, providing high flexibility. These gratings serve as feedback structures for an optically pumped organic laser.

Changes in dielectric constant due to intimate mixing of thiophene molecules with different gaps between ionization energy and electron affinity induce gap variations at the single-particle level, finely tunable by controlling the mixture ratio.

Though single-material organic solar cells are attractive for next-generation photovoltaic technologies, designing new materials with ideal properties remains a challenge. Here, the authors report the use of orientation-dependent molecular electrostatics to realise efficient homojunction devices.

It has been commonly believed that the driving force at the donor-acceptor heterojunction is vital to efficient charge separation in organic solar cells. Here Zhong et al. show that the driving force can be as small as 0.05 eV without compromising the charge transfer rate and efficiency.

Strong light-matter coupling can tune exciton properties but its effect in photovoltaics remains unexplored. Here Nikolis et al. show that the photon energy loss from optical gap to open-circuit voltage can be reduced to unprecedented values by embedding organic solar cells in optical microcavities.

The commercialisation of organic photovoltaic technology calls for research on material degradation mechanisms. Ramirez et al. show that triplet excitons produced by back charge transfer can significantly impact the photo-stability of fullerene-based devices even in the absence of water and oxygen.

Interfaces of organic donor-acceptor blends provide intermolecular charge-transfer states with red-shifted but weak absorption. By introducing an optical micro-cavity; Siegmundet al., enhance their photoresponse to achieve narrowband NIR photodetection with broad spectral tunability.

Photomutiplication-type organic photodetectors (PM-OPDs) are attractive for various next-generation technologies due to their lower cost, higher sensitivity and technological utility. Here, the authors report vacuum-processed narrowband PM-OPDs with enhanced sub-bandgap external quantum efficiency.

The performance of organic semiconductor devices depends heavily on molecular parameters. Here, Schwarze et al. point out that the molecular quadrupole moment largely influences device energy levels and show how quadrupole moments can reduce the energy barrier for charge generation in solar cells.

The suppression of dark current in organic photodetectors (OPDs) is important for maximizing the performance of the devices. Here, the authors report the relationship between the high dark saturation current and the presence of mid-gap trap states in OPDs with a donor–acceptor structure.

A steep absorption edge is preferred for high performance solar cells, but is less common for organic solar cells (OSCs). Here Panhans et al. find that the absorption tails are dominated by zero point vibrations and are responsible for the lowering of the open-circuit voltage and the performance of OSCs.

Molecular doping is routinely used in organic semiconductor devices nowadays, but the physics at play remains unclarified. Tietze et al. describe it as a two-step process and show it costs little, energetically, to dissociate charge transfer complexes due to energetic disorder of organic semiconductors.

Natural photosynthetic systems harvest light to perform selective chemistry on atmospheric molecules such as CO₂. This Review discusses the implementation of bioinspired concepts in engineered light harvesting and catalysis.

Organic solar cells, despite their high power conversion efficiencies, suffer from open circuit voltage losses making them less appealing in terms of applications. Here, the authors, supported with experimental data on small molecule photovoltaic cells, relate open circuit voltage to photovoltaic gap, charge-transfer state energy, and donor-acceptor interfacial morphology.