Organic semiconductor heterojunction (HJ) energy level offsets are modeled using a combination of Marcus theory for electron transfer, and generalized Shockley the dark current density vs voltage $(J\text{\ensuremath{-}}V)$ characteristics. This model is used to fit $J\text{\ensuremath{-}}V$ characteristics several donor-acceptor combinations commonly in thin film organic photovoltaic cells. In with measurements energetics junctions, predicts tradeoffs between junction open-circuit...

We demonstrate high-efficiency organic photovoltaic cells by stacking two hybrid planar-mixed molecular heterojunction in series. Absorption of incident light is maximized locating the subcell tuned to absorb long-wavelength nearest transparent anode, and tuning second closest reflecting metal cathode preferentially short-wavelength solar energy. Using donor, copper phthalocyanine, acceptor, C60, we achieve a maximum power conversion efficiency ηP=(5.7±0.3)% under 1 sun simulated AM1.5G...

We investigate the optical properties of silver nanoparticles used in tandem ultrathin-film organic photovoltaic cells. Experimental results indicate that enhancement an incident field persists into dielectric for distances up to 10nm from center array approximately 5-nm-diameter nanoparticles. Furthermore, this exists far resonant particle surface-plasmon excitation energy. propose a model explain long-range and role cluster spacing, shape, embedding medium with complex constant play...

We demonstrate double-heterostructure copper phthalocyanine/C60 organic photovoltaic cells with series resistances as low 0.1 Ω cm2. A high fill factor of ∼0.6 is achieved, which only slightly reduced at very intense illumination. As a result, the power conversion efficiency increases incident optical density, reaching maximum (4.2±0.2)% under 4–12 suns simulated AM1.5G The cell performance accurately described employing an analysis based on conventional semiconductor p–n junction diodes....

An organic hybrid planar-mixed molecular heterojunction photovoltaic cell, whose photoactive region consists of a mixed layer donor and acceptor molecules sandwiched between homogeneous layers, is demonstrated. A power conversion efficiency (5.0 ± 0.3) % under 1 sun AM1.5G solar illumination achieved. The cell exhibits low resistance to charge transport high exciton-diffusion efficiency.

Abstract In this review, we focus on the field of organic photovoltaic cells based small molecular weight materials. particular, discuss physical processes that lead to photocurrent generation in solar cells, as well various architectures employed optimize device performance. These include donor–acceptor heterojunction for efficient exciton dissociation, blocking layer, mixed or bulk heterojunction, and stacked tandem cell. We show how choice materials with known energy levels absorption...

A double-heterostructure boron subphthalocyanine chloride (SubPc)/C60 thin-film photovoltaic cell exhibits a more than doubled Voc compared to conventional copper phthalocyanine (CuPc)/C60 under 1 sun AM1.5G simulated illumination. The lower oxidation potential of SubPc results in an increase the energy difference between lowest unoccupied molecular orbital acceptor-like material and highest occupied donor-like (referred as interface gap, Ig) by 400 meV. We attribute significant this Ig.

Developing the ability to 3D print various classes of materials possessing distinct properties could enable freeform generation active electronics in unique functional, interwoven architectures. Achieving seamless integration diverse with printing is a significant challenge that requires overcoming discrepancies material addition ensuring all are compatible process. To date, has been limited specific plastics, passive conductors, and few biological materials. Here, we show can be printed...

Thin-film blends or bilayers of donor- and acceptor-type organic semiconductors form the core heterojunction photovoltaic cells. Researchers measure quality cells based on their power conversion efficiency, ratio electrical that can be generated versus incident solar radiation. The efficiency has increased steadily in last decade, currently reaching up to 6%. Understanding combating various loss mechanisms occur processes from optical excitation charge collection should lead efficiencies...

We report valence and conduction band densities of states measured via ultraviolet inverse photoemission spectroscopies on three metal halide perovskites, specifically methylammonium lead iodide bromide cesium (MAPbI3, MAPbBr3, CsPbBr3), grown at two different institutions substrates. These are compared with theoretical (DOS) calculated density functional theory. The qualitative agreement achieved between experiment theory leads to the identification spectral features, allows a precise...

Extremely low energy consumption neuromorphic computing is required to achieve massively parallel information processing on par with the human brain. To this goal, resistive memories based materials ionic transport and extremely operating current are required. allows for power operation by minimizing program, erase, read currents. However, currently used in memories, such as defective HfOx, AlOx, TaOx, etc., cannot suppress electronic (i.e., leakage current) while allowing good transport....

Abstract The anisotropy inherent to many planar organic molecules leads a high sensitivity of various fundamental processes the orientation within films and at heterojunctions. Such include absorption, charge exciton transport, energy levels, transfer, all which are critical solar cell operation. Here,an in‐depth study bilayer cells consisting donor/acceptor interface between zinc phthalocyanine (ZnPc) fullerene (C 60 ) is conducted devices with typically deposited standing up (edge‐on)...

We report on a sol-gel-based technique to fabricate MoO(3) thin films as hole-injection layer for solution-processed or thermally evaporated organic solar cells. The (sMoO(3)) are demonstrated have equal performance layers composed of either PEDOT:PSS (eMoO(3)), and the annealing temperature at which sol-gel begins work is consistent with thermodynamic analysis process. Finally, shelf lifetime devices made sMoO(3) similar equivalent prepared eMoO(3) layer.

Abstract Hybrid organic–inorganic perovskite semiconductors have shown potential to develop into a new generation of light‐emitting diode (LED) technology. Herein, an important design principle for LEDs is elucidated regarding optimal thickness. Adopting thin layer in the range 35–40 nm be critical both device efficiency and stability improvements. Maximum external quantum efficiencies (EQEs) 17.6% Cs 0.2 FA 0.8 PbI 2.8 Br , 14.3% CH 3 NH (MAPbI ), 10.1% formamidinium lead iodide (FAPbI...

We report a comprehensive study of the chemistry perovskite optoelectronic device degradation and show that redox reactions are fundamental to process for CH3NH3PbI3, CsPbI3, CsPbBr3 perovskites with Ag, Al, Yb, or Cr contacts. Using in situ X-ray diffraction measurements, we CH3NH3PbI3 devices equipped Al electrodes; find Al0 rapidly reduces Pb2+ Pb0, converting first (CH3NH3)4PbI6·2H2O then CH3NH3I. In scanning electron microscopy measurements moisture enables continued reaction layers by...

The use of an ITO-free MoO3/Ag/MoO3 anode to control the photon harvesting in PCDTBT:PC70BM solar cells is proposed. At first sight, fact that these anodes possess reduced far-field transmission compared ITO may seem be a disadvantage. But, despite this, we show by carefully tuning resonant optical cavity can enhance external quantum efficiency close band edge PCDTBT, resulting high photocurrent and power conversion on par with ITO.

Two novel indacenodithiophene (IDT) based donor–acceptor conjugated polymers for use in organic field effect transistors and photovoltaic devices are synthesized characterized. The of inclusion two fluorine atoms on the acceptor portion polymer is thoroughly investigated via a range techniques. inductively withdrawing mesomerically donating properties result decrease highest occupied molecular orbital (HOMO), with little lowest unoccupied (LUMO) as demonstrated through density functional...

Organic–inorganic lead halide perovskite semiconductors have recently reignited the prospect of a tunable, solution-processed diode laser, which has potential to impact wide range optoelectronic applications. Here, we demonstrate metal-clad, second-order distributed feedback methylammonium iodide laser that marks significant step toward this goal. Optically pumping device with an InGaN at low temperature, achieve lasing above threshold pump intensity 5 kW/cm2 for durations up ∼25 ns...

One merit of organic–inorganic hybrid perovskites is their tunable bandgap by adjusting the halide stoichiometry, an aspect critical to application in tandem solar cells, wavelength-tunable light emitting diodes (LEDs), and lasers. However, phase separation mixed-halide caused or applied bias results undesirable recombination at iodide-rich domains, meaning open-circuit voltage (VOC) pinning cells infrared emission LEDs. Here, we report approach suppress redistribution self-assembled...

The performance of lead-halide perovskite light-emitting diodes (LEDs) has increased rapidly in recent years. However, most reports feature devices operated at relatively small current densities (<500 mA cm-2 ) with moderate radiance (<400 W sr-1 m-2 ). Here, Joule heating and inefficient thermal dissipation are shown to be major obstacles toward high long lifetime. Several management strategies proposed this work, such as doping charge-transport layers, optimizing device geometry, attaching...