The application of liquid‐exfoliated 2D transition metal disulfides (TMDs) as the hole transport layers (HTLs) in nonfullerene‐based organic solar cells is reported. It is shown that solution ...processing of few‐layer WS2 or MoS2 suspensions directly onto transparent indium tin oxide (ITO) electrodes changes their work function without the need for any further treatment. HTLs comprising WS2 are found to exhibit higher uniformity on ITO than those of MoS2 and consistently yield solar cells with superior power conversion efficiency (PCE), improved fill factor (FF), enhanced short‐circuit current (JSC), and lower series resistance than devices based on poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) and MoS2. Cells based on the ternary bulk‐heterojunction PBDB‐T‐2F:Y6:PC71BM with WS2 as the HTL exhibit the highest PCE of 17%, with an FF of 78%, open‐circuit voltage of 0.84 V, and a JSC of 26 mA cm−2. Analysis of the cells' optical and carrier recombination characteristics indicates that the enhanced performance is most likely attributed to a combination of favorable photonic structure and reduced bimolecular recombination losses in WS2‐based cells. The achieved PCE is the highest reported to date for organic solar cells comprised of 2D charge transport interlayers and highlights the potential of TMDs as inexpensive HTLs for high‐efficiency organic photovoltaics.
The use of liquid exfoliated 2D WS2 and MoS2 as hole‐transporting layers (HTLs) in ultrahigh efficiency organic solar cells is reported. WS2 yields cells with higher power conversion efficiency (PCE), fill‐factor, and short‐circuit current than MoS2 and poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate). When WS2 is introduced as HTL in PBDB‐T‐2F:Y6:PC71BM organic solar cells, a maximum PCE value of 17% is achieved.
Self‐assembled monolayers (SAMs) based on Br‐2PACz (2‐(3,6‐dibromo‐9H‐carbazol‐9‐yl)ethylphosphonic acid) 2PACz (2‐(9H‐Carbazol‐9‐yl)ethylphosphonic acid) and MeO‐2PACz ...(2‐(3,6‐dimethoxy‐9H‐carbazol‐9‐yl)ethylphosphonic acid) molecules were investigated as hole‐extracting interlayers in organic photovoltaics (OPVs). The highest occupied molecular orbital (HOMO) energies of these SAMs were measured at −6.01 and −5.30 eV for Br‐2PACz and MeO‐2PACz, respectively, and found to induce significant changes in the work function (WF) of indium‐tin‐oxide (ITO) electrodes upon chemical functionalization. OPV cells based on PM6 (poly(2,6‐(4,8‐bis(5‐(2‐ethylhexyl‐3‐fluoro)thiophen‐2‐yl)‐benzo1,2‐b:4,5‐b’dithiophene))‐alt‐(5,5‐(1’,3’‐di‐2‐thienyl‐5’,7’‐bis(2‐ethylhexyl)benzo1’,2’‐c:4’,5’‐c’dithiophene‐4,8‐dione)) : BTP‐eC9 : PC71BM (6,6‐phenyl‐C71‐butyric acid methyl ester) using ITO/Br‐2PACz anodes exhibited a maximum power conversion efficiency (PCE) of 18.4 %, outperforming devices with ITO/MeO‐2PACz (14.5 %) and ITO/poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT : PSS) (17.5 %). The higher PCE was found to originate from the much higher WF of ITO/Br‐2PACz (−5.81 eV) compared to ITO/MeO‐2PACz (4.58 eV) and ITO/PEDOT : PSS (4.9 eV), resulting in lower interface resistance, improved hole transport/extraction, lower trap‐assisted recombination, and longer carrier lifetimes. Importantly, the ITO/Br‐2PACz electrode was chemically stable, and after removal of the SAM it could be recycled and reused to construct fresh OPVs with equally impressive performance.
Super SAM: Two self‐assembled monolayers (SAMs; Br‐2PACz and MeO‐2PACz) are investigated as hole‐extracting interlayer in organic photovoltaics and compared against the widely used PEDOT : PSS. Cells based on the ternary bulk‐heterojunction blend PM6 : BTP‐eC9 : PC71BM and ITO/Br‐2PACz as the anode exhibit the highest power conversion efficiency of 18.4 %, outperforming devices with ITO/MeO‐2PACz (14.5 %) and even ITO/PEDOT : PSS (17.5 %).
Over the past few decades, significant progress has been made in the field of photonic processing of electronic materials using a variety of light sources. Several of these technologies have now been ...exploited in conjunction with emerging electronic materials as alternatives to conventional high‐temperature thermal annealing, offering rapid manufacturing times and compatibility with temperature‐sensitive substrate materials among other potential advantages. Herein, recent advances in photonic processing paradigms of metal‐oxide thin‐film transistors (TFTs) are presented with particular emphasis on the use of various light source technologies for the photochemical and thermochemical conversion of precursor materials or postdeposition treatment of metal oxides and their application in thin‐film electronics. The pros and cons of the different technologies are discussed in light of recent developments and prospective research in the field of modern large‐area electronics is highlighted.
Photonic (post)processing of metal‐oxide materials and transistors can offer important advantages over traditional techniques that are of particular relevance to the scalable manufacturing of emerging forms of large‐area electronics. Here, the critical aspects of photonic processing of metal‐oxide electronics are reviewed with emphasis on the pros and cons of the various technologies available to date.
The massive deployment of fifth generation and internet of things technologies requires precise and high-throughput fabrication techniques for the mass production of radio frequency electronics. We ...use printable indium-gallium-zinc-oxide semiconductor in spontaneously formed self-aligned <10 nm nanogaps and flash-lamp annealing to demonstrate rapid manufacturing of nanogap Schottky diodes over arbitrary size substrates operating in 5 G frequencies. These diodes combine low junction capacitance with low turn-on voltage while exhibiting cut-off frequencies (intrinsic) of >100 GHz. Rectifier circuits constructed with these co-planar diodes can operate at ~47 GHz (extrinsic), making them the fastest large-area electronic devices demonstrated to date.
Silver nanowires (Ag NWs) have good promised for flexible and transparent electronics. However, It remains an open question on how to achieve large-scale printing of Ag NWs with high optical ...transparency, electrical conductivity, and mechanical durability for practical applications, though extensive research has been conducted for more than a decade. In this work, we propose a possible solution that integrates screen printing of Ag NWs with flash-light sintering (FLS). We demonstrate that the use of low-concentration, screen-printable Ag NW ink enables large-area and high-resolution patterning of Ag NWs. A critical advantage comes from the FLS process that allows low-temperature processing, short operational time, and high output rate-characteristics that fit the scalable manufacturing. Importantly, we show that the resultant Ag NW patterns feature low sheet resistance (1.1-9.2 Ohm sq−1), high transparency (75.2-92.6%), and thus a remarkable figure of merit comparable to state of the art. These outstanding properties of Ag NW patterns, together with the scalable fabrication method we propose, would facilitate many Ag NW-based applications, such as transparent heaters, stretchable displays, and wearable devices; here, we demonstrate the novel design of flexible and transparent radio frequency 5G antennas.
Molecular doping has recently been shown to improve the operating characteristics of organic photovoltaics (OPVs). Here, we prepare neutral Diquat (DQ) and use it as n-dopant to improve the ...performance of state-of-the-art OPVs. Adding DQ in ternary bulk-heterojunction (BHJ) cells based of PM6:Y6:PC71BM is found to consistently increase their power conversion efficiency (PCE) from 16.7 to 17.4%. Analyses of materials and devices reveal that DQ acts as n-type dopant and morphology modifier for the BHJ leading to observable changes in its surface topography. The resulting n-doped BHJs exhibit higher optical absorption coefficients, balanced ambipolar transport, longer carrier lifetimes and suppressed bimolecular recombination, which are ultimately responsible for the increased PCE. The use of DQ was successfully extended to OPVs based on PM6:BTP-eC9:PC71BM for which a maximum PCE of 18.3% (uncertified) was achieved. Our study highlights DQ as a promising dopant for application in next generation organic solar cells.
Two-dimensional transition
metal carbides (MXenes) are of great
interest as electrode materials for a variety of applications, including
solar cells, due to their tunable optoelectronic properties, ...high
metallic conductivity, and attractive solution processability. However,
thus far, MXene electrodes have only been exploited for lab-scale
device applications. Here, to demonstrate the potential of MXene electrodes
at an industry-relevant level, we implemented a scalable spray coating
technique to deposit highly conductive (
ca
. 8000
S/cm, at a
ca
. 55 nm thickness) Ti
3
C
2
T
x
films (
T
x
: surface functional groups,
i
.
e
., −OH, −O, −F)
via
an automated spray system. We employed these Ti
3
C
2
T
x
films as rear electrodes for silicon heterojunction solar cells
as a proof of concept. The spray-deposited MXene flakes have formed
a conformal coating on top of the indium tin oxide (ITO)-coated random
pyramidal textured silicon wafers, leading to >20% power conversion
efficiency (PCE) over both medium-sized (4.2 cm
2
) and large
(243 cm
2
,
i
.
e
., industry-sized
6 in. pseudosquare wafers) cell areas. Notably, the Ti
3
C
2
T
x
-rear-contacted
devices have retained around 99% of their initial PCE for more than
600 days of ambient air storage. Their performance is comparable with
state-of-the-art solar cells contacted with sputtered silver electrodes.
Our findings demonstrate the high-throughput potential of spray-coated
MXene-based electrodes for solar cells in addition to a wider variety
of electronic device applications.
The rising concentration of organic micro-pollutants (OMPs) in water resources has become a major concern for aquatic ecosystems and human health. Advanced oxidation processes (AOPs), based on ...ultraviolet (UV) photolysis and photochemical reactions, have been suggested for the degradation of various micropollutants present in water and wastewater. However, the application of these methods on large scale is limited due to the long treatment times. Here we evaluate the efficiency of high-intensity pulsed light treatment (HIPL) for the degradation of organic compounds in aqueous conditions. A solution containing 11 OMPs was treated with short (<2 ms) and high-intensity light pulses produced by a Xenon flash lamp. It was observed that the HIPL parameters, such as the number of pulses and optical energy dose, have a significant impact on the efficiency of the treatment. The main advantage of HIPL is the fast kinetics that allows efficient photodegradation of OMPs from the aqueous solution rapidly and within milliseconds. The present work showcases the potential of HIPL technique for the post-treatment of contaminated water containing pharmaceuticals and endocrine disruptor compounds.
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•Polluted water was treated with high intensity light generated by a flash lamp•The high-intensity light was provided in the form of short pulses•The HIPL allows photodegradation of micropollutants within milliseconds•The effect of light intensity and number of pulses was evaluated
The low carrier mobility of organic semiconductors and the high parasitic resistance and capacitance often encountered in conventional organic Schottky diodes hinder their deployment in emerging ...radio frequency (RF) electronics. Here, these limitations are overcome by combining self‐aligned asymmetric nanogap electrodes (≈25 nm) produced by adhesion lithography, with a high mobility organic semiconductor, and RF Schottky diodes able to operate in the 5G frequency spectrum are demonstrated. C16IDT‐BT is used, as the high hole mobility polymer, and the impact of p‐doping on the diode performance is studied. Pristine C16IDT‐BT‐based diodes exhibit maximum intrinsic and extrinsic cutoff frequencies (fC) of >100 and 6 GHz, respectively. This extraordinary performance is attributed to the planar nature of the nanogap channel and the diode's small junction capacitance (<2 pF). Doping of C16IDT‐BT with the molecular p‐dopant C60F48 improves the diode's performance further by reducing the series resistance resulting to intrinsic and extrinsic fC of >100 and ≈14 GHz respectively, while the DC output voltage of an RF rectifier circuit increases by a tenfold. Our work highlights the importance of the planar nanogap architecture and paves the way for the use of organic Schottky diodes in large‐area RF electronics of the future.
Combining asymmetric co‐planar nanogap electrodes with a p‐doped organic polymer semiconductor yields Schottky diodes that are capable of operating at 14 GHz, making them the fastest organic electronic devices reported to date.
Recent advances in solution-processable semiconducting colloidal quantum dots (CQDs) have enabled their use in a range of (opto)electronic devices. In most of these studies, device fabrication ...relied almost exclusively on thermal annealing to remove organic residues and enhance inter-CQD electronic coupling. Despite its widespread use, however, thermal annealing is a lengthy process, while its effectiveness to eliminate organic residues remains limited. Here, we exploit the use of xenon flash lamp sintering to post-treat solution-deposited layers of lead sulfide (PbS) CQDs and their application in n-channel thin-film transistors (TFTs). The process is simple, fast, and highly scalable and allows for efficient removal of organic residues while preserving both quantum confinement and high channel current modulation. Bottom-gate, top-contact PbS CQD TFTs incorporating SiO2 as the gate dielectric exhibit a maximum electron mobility of 0.2 cm2 V–1 s–1, a value higher than that of control transistors (≈10–2 cm2 V–1 s–1) processed via thermal annealing for 30 min at 120 °C. Replacing SiO2 with a polymeric dielectric improves the transistor’s channel interface, leading to a significant increase in electron mobility to 3.7 cm2 V–1 s–1. The present work highlights the potential of flash lamp annealing as a promising method for the rapid manufacture of PbS CQD-based (opto)electronic devices and circuits.
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