Abstract Semi-transparent perovskite solar cells are highly attractive for a wide range of applications, such as bifacial and tandem cells; however, the power conversion efficiency semi-transparent devices still lags behind due to missing suitable transparent rear electrode or deposition process. Here we report low-temperature process efficient planar cells. A hybrid thermal evaporation–spin coating technique is developed allow introduction PCBM in regular device configuration, which...

Abstract This review summarizes the current status of Cu(In,Ga)(S,Se) 2 (CIGS) thin film solar cell technology with a focus on recent advancements and emerging concepts intended for higher efficiency novel applications. The developments trends research in laboratories industrial achievements communicated within last years are reviewed, major linked to alkali post deposition treatment composition grading CIGS, surface passivation, buffer, transparent contact layers emphasized. Encouraging...

Abstract Flexible, lightweight Cu(In,Ga)Se 2 (CIGS) solar cells grown on polymer substrates are a promising technology with fast growing market prospects. However, power conversion efficiencies of at low temperatures (≈450 °C) remain below the high temperature glass substrates. This contribution discusses impact cell efficiency process improvements low‐temperature CIGS deposition flexible polyimide and Different strategies for incorporation alkali elements into evaluated based large number...

We achieved automated optical control over coherent lattice responses that were both time- and position-dependent across macroscopic length scales. In our experiments, spatiotemporal femtosecond pulse shaping was used to generate excitation light fields directed toward distinct regions of crystalline samples, producing terahertz-frequency vibrational waves emanated outward from their multiple origins at lightlike speeds. Interferences among the resulted in fully specified far-field...

Summary Two‐photon absorption and emission spectra for fluorophores relevant in cell imaging were measured using a 45 fs Ti:sapphire laser, continuously tuneable optical parametric amplifier the excitation range 580–1150 nm an multichannel analyser. The measurements included DNA stains, fluorescent dyes coupled to antibodies as well organelle trackers, e.g. Alexa Bodipy dyes, Cy2, Cy3, DAPI, Hoechst 33342, propidium iodide, FITC rhodamine. In accordance with two‐photon theory, majority of...

A promising way to enhance the efficiency of CIGS solar cells is by combining them with perovskite in tandem devices. However, so far, such devices had limited due challenges developing NIR-transparent top cells, which allow photons energy below band gap be transmitted bottom cell. Here, a process for fabrication presented, enables power conversion efficiencies up 12.1% combined an average sub-band transmission 71% wavelength between 800 and 1000 nm. The combination cell enabled device 19.5%...

Abstract The knowledge of minority carrier lifetime a semiconductor is important for the assessment its quality and design electronic devices. Time-resolved photoluminescence (TRPL) measurements offer possibility to extract effective lifetimes in nanosecond range. However, it difficult discriminate between surface bulk recombination consequently properties cannot be estimated reliably. Here we present an approach constrain systematically parameters semiconducting layers reduces finding roots...

Abstract Metal halide perovskite solar cells (PSCs) have gained tremendous attention due to their high power conversion efficiencies (PCEs) and potential for low‐cost manufacturing. Their wide tunable bandgap makes perovskites an ideal candidate tandem (TSCs) with well‐established narrow photovoltaic technologies, such as crystalline silicon Cu(In,Ga)Se 2 , boost the PCEs beyond Shockley–Queisser limit at affordable additional cost. Although perovskite‐based TSCs shown rapid progress over...

We present broadband group velocity dispersion (GVD) measurements of commercially available ultra-high numerical aperture fibers (UHNA1, UHNA3, UHNA4, UHNA7 and PM2000D from Coherent-Nufern). Although these are attractive for management in ultrafast fiber laser systems the 2 {\mu}m wavelength region, experimental data literature is scarce inconsistent. Here we demonstrate using spectral interferometry technique covering typically used erbium, thulium holmium emission bands. The results...

Abstract State‐of‐the‐art Cu(In,Ga)Se 2 (CIGS) solar cells are grown with considerably substoichiometric Cu concentrations. The resulting defects, as well potential improvements through increasing the concentration, have been known in field for many years. However, so far, high concentrations show decreased photovoltaic parameters. In this work, it is shown that RbF postdeposition treatment of CuInSe allows capturing benefits from improved absorber quality content. A reduced defect density...

We describe highly efficient and stable bifacial perovskite solar cells incorporating carbon nanotube network films as a back contact enabling perovskite/CIS 4-terminal tandem to reach apower conversion efficiency of over 27%.

Between electronics and photonics there exists a frequency gap of approximately two octaves, i.e., the range between 100 GHz 10 THz, across which are limited capabilities for signal generation, control, guidance, processing. Here, we demonstrate that phonon-polaritons in ionic crystals like LiNbO 3 or LiTaO may be used to bridge this gap. The ability directly visualize polariton fields through real-space imaging, generate arbitrary THz waveforms use temporally and/or spatially shaped optical...

A new diffraction-based method is proposed and demonstrated for simultaneous shaping of both the phase amplitude femtosecond laser pulses by use a phase-only two-dimensional spatial light modulator. The suppresses certain types temporal replica features ordinarily observed in pulse owing to imperfections modulator devices allows multiplexed outputs suitable various applications.

We show that a resonant response with very high quality factors can be achieved in periodic metamaterials by radiatively coupling their structural elements. The is mediated lattice modes and efficiently controlled tuning the periodicity. Using recently developed terahertz (THz) near-field imaging technique conventional far-field spectroscopy together numerical simulations we pinpoint underlying mechanisms. In strong regimes identify avoided crossings between plasmonic eigenmodes diffractive modes.

Using terahertz near-field imaging we experimentally investigate the resonant electromagnetic field distributions behind a split-ring resonator and its complementary structure with sub-wavelength spatial resolution. For out-of-plane components verify complementarity of electric magnetic fields as predicted by Babinet's principle. This duality near-fields can be used to indirectly map close metallic microstructures measuring their analogues which is particularly useful since are still...

The possibility of growing perovskite solar cells on flexible substrates can be seen as an exciting opportunity, allowing high throughput roll-to-roll manufacturing with a low embodied energy, and creating new applications in buildings, vehicles, portable electronics internet-of-things based devices. Flexible have previously been developed polymer such polyethylene terephthalate (PET) or naphthalate (PEN) which are vulnerable to the ingress moisture. Here we report development grown typical...

Compositional grading has been widely exploited in highly efficient Cu(In,Ga)Se2, CdTe, GaAs, quantum dot solar cells, and this strategy the potential to improve performance of emerging perovskite cells. However, realizing maintaining compositionally graded absorber from solution processing is challenging. Moreover, operational stability cells under long-term heat/light soaking not demonstrated. In study, a facile partial ion-exchange approach reported achieve layers. Incorporating...

Absorbers for planar perovskite solar cells are often prepared by two‐step deposition methods, where a thick compact PbI 2 layer is deposited followed conversion to using CH 3 NH I solution. The surface of the precursor quickly reacts with solution, which hinders further diffusion into layer, consequently leading significant amounts residual at room temperature. Here, we report novel concept that employs porous nanostructured consisting nanoplates rapidly prepare single phase layer....

We realized a phase retrieval technique using terahertz (THz) radiation as an alternative to THz digital holography, named ptychography.Ptychography has been used in x-ray imaging groundbreaking improvement of conventional coherent diffraction imaging.Here we show that ptychography can be performed at frequencies too.We reconstructed amplitude and object with both simulated real data.Lateral resolution accounts <2λ, while depth variations low λ∕30 assessed.

Four-terminal (4-T) tandem solar cells (e.g., perovskite/CuInSe2 (CIS)) rely on three transparent conductive oxide electrodes with high mobility and low free carrier absorption in the near-infrared (NIR) region. In this work, a reproducible In2O3:H (IO:H) film deposition process is developed by independently controlling H2 O2 gas flows during magnetron sputtering, yielding value up to 129 cm2 V-1 s-1 highly crystallized IO:H films annealed at 230 °C. Optimization of partial pressures further...

Abstract A novel molecular‐ink deposition route based on thiourea and N , ‐dimethylformamide (DMF) that results in a certified solar cell efficiency world record for non‐vacuum deposited CuIn(S,Se) 2 (CIS) absorbers with bandgap of 1.0 eV, is presented. It found by substituting the widely employed solvent dimethyl sulfoxide DMF, coordination chemistry InCl 3 could be altered, dramatically improving ink stability, enabling up to tenfold increased concentrations, omitting necessity elevated...

Abstract The power conversion efficiency of solar cells strongly depends on the open‐circuit voltage which, in turn, recombination activity within device. A possible source detrimental charge carrier is band tails. An empirical linear relationship between loss and Urbach energy tails has been shown past. Here we discuss how influence radiative nonradiative bulk absorber. First, show through photoluminescence that can be willfully tuned state‐of‐the‐art thin‐film Cu (In,Ga)Se 2 (CIGSe)...