We present the Focus-Induced Photoresponse (FIP) technique, a novel approach to optical distance measurement. It takes advantage of a universally-observed phenomenon in photodetector devices, an irradiance-dependent responsivity. This means that the output from a sensor is not only dependent on the total flux of incident photons, but also on the size of the area in which they fall. If probe light from an object is cast on the detector through a lens, the sensor response depends on how far in or out of focus the object is. We call this the FIP effect. Here we demonstrate how to use the FIP effect to measure the distance to that object. We show that the FIP technique works with different sensor types and materials, as well as visible and near infrared light. The FIP technique operates on a working principle, which is fundamentally different from all established distance measurement methods and hence offers a way to overcome some of their limitations. FIP enables fast optical distance measurements with a simple single-pixel detector layout and minimal computational power. It allows for measurements that are robust to ambient light even outside the wavelength range accessible with silicon.

We present the Focus-Induced Photoresponse (FIP) technique, a novel approach to optical distance measurement. It takes advantage of a widely-observed phenomenon in photodetector devices: a nonlinear, irradiance-dependent photoresponse. This means that the output from a sensor is dependent on the total number of photons incident and the size of the area in which they fall. With a certain arrangement of sensor and lens, this phenomenon will cause the output of the sensor to change based on how far in or out of focus an object is. We call this the FIP effect. Here we demonstrate how to use the FIP effect for distance measurements. We show that this technique works with different sensor materials, device types, as well as visible and near infrared light. In principle, any sensor exhibiting a photoresponse that depends nonlinearly on irradiance could be used with the FIP technique. It is our belief that the FIP technique can become an important method for measuring distance.

Aliphatic substituent effects on the HOMO energy levels and the ability to transport charge and form stable molecular glasses of systematically modified spiro-OMeTAD analogues were investigated.

Small-molecule fluorene HTMs were synthesized and tested in perovskite solar cell, PCE of up to 19.96% was reached.

Thermal stability of hybrid solar cells containing spiro-OMeTAD as hole-transporting layer is investigated. It is demonstrated that fully symmetrical spiro-OMeTAD is prone to crystallization, and growth of large crystalline domains in the hole-transporting layer is one of the causes of solar cell degradation at elevated temperatures, as crystallization of the material inside the pores or on the interface affects the contact between the absorber and the hole transport. Suppression of the crystal growth in the hole-transporting layer is demonstrated to be a viable tactic to achieve a significant increase in the solar cell resistance to thermal stress and improve the overall lifetime of the device. Findings described in this publication could be applicable to hybrid solar cell research as a number of well-performing architectures rely heavily upon doped spiro-OMeTAD as hole-transporting material.

β-Crustacyanin (β-CR) is a pigment protein responsible for the blue color of lobsters. We show using correlated ab initio calculations how the protein environment tunes the chromophores of β-CR through electrostatic and steric effects.

Accurate predictions of photoexcitation properties are a major challenge for modern methods of theoretical chemistry. We show here how approximate coupled-cluster singles and doubles (CC2) calculations in combination with the reduced virtual space (RVS) approach can be employed in studies of excited states of large biomolecular systems. The RVS-CC2 approach is used for accurately predicting optical properties of the p-hydroxybenzylidene-dihydroimidazolinone (p-HBDI) chromophore embedded in green fluorescent protein (GFP) models using quantum mechanical calculations in combination with large basis sets. We study the lowest excited states for the isolated and protein-embedded chromophore in two different protonation states, and show how omitting high-lying virtual orbitals in the RVS calculation of excitation energies renders large-scale CC2 studies computationally feasible. We also discuss how the error introduced by the RVS approach can be systematically estimated and controlled. The obtained CC2 excitation energies of 3.13-3.27 and 2.69-2.77 eV for the two protonation states of different protein models are in excellent agreement with the maxima of the experimental absorption spectra of 3.12-3.14 and 2.61-2.64 eV, respectively. Thus, the calculated energy splitting between the excited states of the two protonation states is 0.44-0.52 eV, which agrees very well with the experimental value of 0.48-0.51 eV. The calculations at the RVS-CC2 level on the protein models show the importance of using large QM regions in studies of biochromophores embedded in proteins.

AbstractDas Pigment β‐Crustacyanin (β‐CR) verursacht die Farbe des blauen Hummers. Wir zeigen mithilfe korrelierter Ab‐initio‐Rechnungen, wie die Proteinumgebung die Farbe der β‐CR‐Farbstoffe mittels elektrostatischer und sterischer Effekte bestimmt.

The energy levels of new metal-free organic dyes for dye-sensitized solar cells have been investigated by the photoemission in air, UV-Vis absorption and cyclic voltammetry methods in the solutions of the dye molecules, in films of the pure dyes and in the dyes adsorbed on nanoporous TiO2. Significant differences of the energy levels have been found depending on the dye environment. For the best level of tuning in a solar cell, the energy levels are to be determined for the dyes adsorbed on the TiO2 surface. The absorbed photon conversion to current efficiency (APCE) of the solar cells was evaluated and compared with the incident photon quantum efficiency (IPCE). The results obtained show that the IPCE is dependent on the light quanta energy and reaches a maximum value when the light quanta energy is about 0.3 eV higher than the light absorption threshold.

A new type of dendrimer-like hydrazone hole transporting materials have been reported and their thermal, optical, electrochemical and photophysical properties are investigated and applicability in construction of hybrid solar cells is evaluated. It was found that hole mobility in these hydrazones reaches respectable 2.5 x 10(-3) cm(2) V-1 s at strong electric fields, which puts them on a par with majority of the best performing amorphous, solution-processed hole transporting materials used today. (C) 2015 Elsevier Ltd. All rights reserved.

D-pi-A architecture metal-free organic dyes, with a tetrahydroquinoline unit as electron donor, were designed and synthesized for solid-state dye-sensitized solar cells. The sensitizer series was designed to develop a structure-property relationship. These dyes are obtained from relatively cheap starting materials, without the use of expensive catalysts, rigorously anhydrous or oxygen-free conditions. The highest solid-state device conversion efficiency (eta) 33% (J(SC) = -5.9 mA cm(-2), V-OC = 780 mV) and fill factor FF = 0.72 under 100 mW cm(-2) (AM 1.5G) solar irradiation was achieved with dye D4 employing a hydrazone fragment as the spacer between the donor 3-alkoxy-1-phenyl-1,2,3,4-tetrahydroquinoline and the rhodanine acceptor of the sensitizer. (C) 2014 Elsevier Ltd. All rights reserved.

In this contribution we use computational tools to investigate the reaction of alcohol substrates with reactive nitrogen oxide species such as N2O3 and N2O4, leading to the formation of alkyl nitrites. These nitrites are interesting intermediates which can be processed to various valuable chemicals such as ketones/aldehydes and dimethyl oxalate while regenerating NO x . As such, NO x is used as an oxidation mediator, converting alcohol substrates to more reactive nitrites which can be selectively converted to more desired compounds, closing a catalytic cycle in NO x species.

D-D-pi-A architecture metal-free organic dyes, containing a hydrazone moiety as an auxiliary donor were designed and synthesized for solid-state dye-sensitized solar cells. The sensitizer series was designed to develop a structure-property relationship. These dyes were obtained from the relatively cheap starting materials, without the use of expensive catalysts, rigorously anhydrous or oxygen-free conditions. The highest solid-state device conversion efficiency 3.9% (J(sc) = -7.9 mA cm(-2), V-OC = 760 mV) and fill factor 0.65 under 100 mWcm(-2) (AM 1.5G) solar irradiation were achieved with the dye D3 containing a methoxy group attached to the triphenylamine donor unit employed between the hydrazone moiety and rhodanine acceptor of the sensitizer. (C) 2014 Elsevier Ltd. All rights reserved.

New metal-free organic dyes for solid-state dye-sensitized solar cells, employing a hydrazone fragment, have been synthesized and investigated. These sensitizers are obtained from relatively cheap starting materials, without the use of expensive catalysts, rigorously anhydrous or oxygen-free conditions. Correlation between the structure of hydrazone-containing dyes and the performance of the solid-state DSSC is investigated. The highest obtained solid-state device conversion efficiency, under standard AM 1.5G illumination (100 mW cm(-2)), was 4.5% (J(SC) = 8.03 mA cm(-2), V-OC = 880 mV, FF = 0.64).