Colloidal quantum dots have emerged as a material platform for low-cost high-performance optoelectronics. At the heart of optoelectronic devices lies formation junction, which requires intimate contact n-type and p-type semiconductors. Doping in bulk semiconductors has been largely deployed many decades, yet electronically active doping remained challenge demonstration robust functional had thus far elusive. Here we report an device, dot homojunction solar cell, based on heterovalent cation...

Developing low-cost photovoltaic absorbers that can harvest the short-wave infrared (SWIR) part of solar spectrum, which remains unharnessed by current Si-based and perovskite technologies, is a prerequisite for making high-efficiency, tandem cells. Here, PbS colloidal quantum dot (CQD) cells employing hybrid inorganic-organic ligand exchange process results in an external efficiency 80% at 1.35 µm are reported, leading to short-circuit density 34 mA cm-2 power conversion (PCE) up 7.9%,...

Surface passivation of PbS colloidal quantum dots (QDs) with iodide has been used in highly efficient solar cells. Iodide is typically achieved by ligand-exchange processes on QD films. Complementary to this approach, herein we present a nonintrusive solution-based strategy for doping QDs further optimize cell performance. The step applied situ at the end synthesis QDs. optimum precursor I/Pb ratio found be 1.5–3% range which substitutes S without excessively altering dots' surface...

The power conversion efficiency of colloidal PbS‐quantum‐dot (QD)‐based solar cells is significantly hampered by lower‐than‐expected open circuit voltage ( V OC ). deficit considerably higher in QD‐based compared to other types existing due in‐gap trap‐induced bulk recombination photogenerated carriers. Here, this study reports a ligand exchange procedure based on mixture zinc iodide and 3‐mercaptopropyonic acid reduce the without compromising high current density. This layer‐by‐layer solid...

To realize the full potential of colloidal quantum dot (CQD) based solar cells, it is important to address issue large open-circuit voltage (VOC) deficit which a major roadblock in reaching higher efficiencies. The origin VOC these cells lies primarily presence sub-bandgap trap states QDs. Here, we present synergistic engineering framework passivate PbS QDs through chemical surface passivation and remote exploiting ligand architecture engineering. In particular, form bulk nanoheterojunctions...

More-efficient charge collection and suppressed trap recombination in colloidal quantum dot (CQD) solar cells is achieved by means of a bulk nano-heterojunction (BNH) structure, which p-type n-type materials are blended on the nanometer scale. The improved performance BNH devices, compared with that bilayer displayed higher photocurrents open-circuit voltages (resulting from passivation mechanism). As service to our authors readers, this journal provides supporting information supplied...

Lead halide perovskite nanocrystals (NCs) are currently emerging as one of the most interesting solution-processed semiconductors because they possess high photoluminescence quantum yield (PLQY) and color tunability through anion exchange reactions or confinement. Here, we show efficient solar cells based on mixed-halide (CsPbBrI2) NCs obtained via under ambient conditions. We performed in concentrated NC solutions with I–, thus inducing a PL red shift up to 676 nm obtaining PLQY film (65%)....

Understanding the nanomorphology of polymer-based solar cells is key to improving device efficiencies. A detailed study changes in polymer cell morphology at molecular level and real time under process conditions presented. Using low voltage, high resolution electron microscopy (LVHREM) we observe mechanisms PCBM-rich domain migration provide evidence for vertical segregation within bulk heterojunction increased crystallinity both P3HT PCBM. The results highlights fact that P3HT:PCBM should...

In just 20 years of history, the field optomechanics has achieved impressive progress, stepping into quantum regime 5 ago. Such remarkable advance relies on technological revolution nano-optomechanical systems, whose sensitivity towards thermal decoherence is strongly limited due to their ultra-low mass. Here we report a hybrid approach pushing nano-optomechanics even lower scales. The concept synthesising an efficient optical scatterer at tip singly clamped carbon nanotube resonators. We...

Abstract Defects play an important role in tailoring the optoelectronic properties of materials. Supported by density functional theory (DFT) calculations, herein it is demonstrated that sulphur vacancies are able to engineer sub‐band gap photoresponse short‐wave infrared range due formation in‐gap states Bi 2 S 3 single crystals. Sulfurization and subsequent refill result faster response but limit spectral near as determined bandgap . A facile chemical treatment then explored accelerate...

We report advances in the growth, characterization and photovoltaic properties of SnS nanocrystals, with controlled < 10 nm size, their inclusion into a lead chalcogenide solar cell. The SnS/PbS nanocrystalline film heterojunction is shown to display type II band alignment, which direction flow photocurrent depends on order layers not relative work functions contacts. On placing layer next indium tin oxide (ITO) cathode we observe dramatic increase V(oc) as much 0.45 V. Our results suggest...

Two-terminal tandem cell architectures are believed to be an effective way further improve the power conversion efficiency in solution processed photovoltaics. To design efficient solar cell, two key issues need considered. First, subcells with well-matched currents and complementary absorption characteristics a prerequisite for high efficiency. Second, identifying appropriate intermediate layer (IML) connect is necessary minimize optical electronic losses. PbS colloidal quantum dots (CQDs)...

We report on a nanomechanical engineering method to monitor matter growth in real time via e-beam electromechanical coupling. This relies the exceptional mass sensing capabilities of resonators. Focused electron beam induced deposition (FEBID) is employed selectively grow platinum particles at free end singly clamped nanotube cantilevers. The has two functions: it allows both material and track deposited by probing noise-driven mechanical resonance nanotube. On one hand, this detection...

We report on an extensive spectroscopic investigation of the impact substitutional doping optoelectronic properties PbS colloidal quantum dot (CQD) solids. N-doping is provided by Bi incorporation during CQD synthesis as well post-synthetically via cation exchange reactions. The data indicate a systematic quenching excitonic absorption and luminescence appearance two dopant-induced contributions at lower energies to free exciton. Temperature-dependent photoluminescence indicates presence...

Inorganic nanorod/conjugated polymer composites are advanced materials for photovoltaics. It is shown that a post-synthesis treatment of PbS nanocrystal/poly(2-methoxy-5-(2-ethyl-hexyloxy)-p-phenylene vinylene) (MEH-PPV) composites, synthesized by low-temperature and surfactant-free method, results in the controlled assembly nanorods through oriented attachment nanocrystals. Supporting information this article available on WWW under...

High efficiency organic and hybrid solar cells create demand for novel electron acceptor materials that possess appropriate energetic band levels bandgap efficient energy harnessing. We present bulk heterojunction devices based on P3HT bismuth sulfide nanocrystals, a semiconductor environmentally friendly compounds, with power conversion of 1% NIR sensitization at 700 nm 30%, among the highest ever reported P3HT.

The performance of ZnO/PbS colloidal quantum dot (CQD)-based heterojunction solar cells is hindered by charge carrier recombination at the interface. Reducing interfacial can improve collection and photocurrent device. Here we report use a mixed nanocrystal (MNC) buffer layer comprising zinc oxide nanocrystals lead sulfide dots respective Remote trap passivation PbS CQDs taking place within this MNC reduces electron back transfer which in turn improves efficiency. Upon addition layer,...

Perovskite nanocrystal light-emitting diodes (LEDs) employing architecture comprising a ZnO nanoparticles electron-transport layer and conjugated polymer hole-transport have been fabricated. The obtained LEDs demonstrate maximum external-quantum-efficiency of 6.04%, luminance 12998 Cd/m2 stable electroluminescence at 519 nm. Importantly, such high efficiency brightness achieved by solution processed transport layers, formamidinium lead bromide nanocrystals (CH(NH2)2PbBr3 NCs) synthesized...

The creation of white and multicoloured 3D-printed objects with high color fidelity via powder sintering processes is currently limited by discolouration from thermal sensitizers used in the printing process. Here, we circumvent this problem using switchable, photochromic tungsten oxide nanoparticles, which are colorless even at concentrations. Upon ultraviolet illumination, nanoparticles can be reversibly activated, making them highly absorbing infrared. Their strong infrared absorption...

Lead oxide nanocrystals are synthesised by injecting oxygen gas into an air and moisture free complex of Pb oleylamine oleic acid in octadecene. Using various characterization methods including fabrication testing photovoltaic devices we explore the material properties application lead nanocrystal films.