Journal of Photonics for Energy 

About: Journal of Photonics for Energy is an academic journal published by SPIE. The journal publishes majorly in the area(s): Solar cell & Solar energy. It has an ISSN identifier of 1947-7988. Over the lifetime, 561 publications have been published receiving 7025 citations.

Transparent electrodes for organic optoelectronic devices: a review

Abstract: Transparent conductive electrodes are one of the essential components for organic optoelectronic devices, including photovoltaic cells and light-emitting diodes. Indium-tin oxide (ITO) is the most common transparent electrode in these devices due to its excellent optical and electrical properties. However, the manufacturing of ITO film requires precious raw materials and expensive processes, which limits their compatibility with mass production of large-area, low-cost devices. The optical/electrical properties of ITO are strongly dependent on the deposition processes and treatment conditions, whereas its brittleness and the potential damage to underlying films during deposition also present challenges for its use in flexible devices. Recently, several other transparent conductive materials, which have various degrees of success relative to commercial applications have been developed to address these issues. Starting from the basic properties of ITO and the effect of various ITO surface modification methods, here we review four different groups of materials, doped metal oxides, thin metals, conducting polymers, and nanomaterials (including carbon nanotubes, graphene, and metal nanowires), that have been reported as transparent electrodes in organic optoelectronic materials. Particular emphasis is given to their optical/electrical and other material properties, deposition techniques, and applications in organic optoelectronic devices.

Pathways toward high-performance perovskite solar cells: review of recent advances in organo-metal halide perovskites for photovoltaic applications

Abstract: Organo-metal halide perovskite–based solar cells have been the focus of intense research over the past five years, and power conversion efficiencies have rapidly been improved from 3.8 to >21%. This article reviews major advances in perovskite solar cells that have contributed to the recent efficiency enhancements, including the evolution of device architecture, the development of material deposition processes, and the advanced device engineering techniques aiming to improve control over morphology, crystallinity, composition, and the interface properties of the perovskite thin films. The challenges and future directions for perovskite solar cell research and development are also discussed.

Recent advances in light outcoupling from white organic light-emitting diodes

Abstract: Organic light-emitting diodes (OLEDs) have been successfully introduced to the smartphone display market and have geared up to become contenders for applications in general illumination where they promise to combine efficient generation of white light with excellent color quality, glare-free illumination, and highly attractive designs. Device efficiency is the key requirement for such white OLEDs, not only from a sustainability perspective, but also because at the high brightness required for general illumination, losses lead to heating and may, thus, cause rapid device degradation. The efficiency of white OLEDs increased tremendously over the past two decades, and internal charge-to-photon conversion can now be achieved at ∼100% yield. However, the extraction of photons remains rather inefficient (typically <30%). Here, we provide an introduction to the underlying physics of outcoupling in white OLEDs and review recent progress toward making light extraction more efficient. We describe how structures that scatter, refract, or diffract light can be attached to the outside of white OLEDs (external outcoupling) or can be integrated close to the active layers of the device (internal outcoupling). Moreover, the prospects of using top-emitting metal–metal microcavity designs for white OLEDs and of tuning the average orientation of the emissive molecules within the OLED are discussed.

Review of recent progress in multilayer solution-processed organic light-emitting diodes

Abstract: Organic light-emitting diodes (OLEDs) have become a promising candidate for lighting and display applications. High efficiency OLEDs require a multilayer device architecture to provide exciton confinement and balance charge transport. Conventional OLEDs are made by vacuum process, and the manufacturing cost can be reduced by solution processing. However, unlike vacuum-deposited OLEDs, solution-processed multilayer OLEDs are more challenging to make. The key for multilayer solution processing is to have the layer structure which can withstand solvents used in subsequent processing. We review the materials’ strategies to make multilayer solution-processed OLEDs. Specifically, we will discuss the use of cross-linkable organic materials, metal oxides, and orthogonal solvent systems to deposit various functional layers in an OLED.

Organic light-emitting-diode lighting overview

Abstract: For organic light-emitting-diode (OLED) lighting to be successful, it is critical that it be properly positioned in the marketplace. It is also critical that both the performance and cost be competitive against other lighting technologies in the selected marketplace. This presentation gives an overview of OLED lighting technology from these perspectives. It shows that OLED lighting products should be positioned as luminaires and not light bulbs, which affects both the performance and price expectations. Laboratory OLED devices already demonstrated efficacies that are more than competitive against luminaires based on other lighting technologies. There is potential for substantial further improvement in efficacy. The greatest opportunities come from light-extraction efficiency improvements and from an improved blue emitting system. There has been great recent progress in the OLED device lifetime. To be acceptable as luminaires, however, OLED may need even more lifetime improvements. Not all the improvements need to come from OLED technology improvement, however. We discuss other means to effectively improve the lifetime of OLED lighting panels and show why there is optimism that, with volume production, OLED lighting can be competitive against other luminaires even on the first-cost