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Water disinfection is an essential process that provides safe water by inactivating pathogens that cause waterborne diseases. However, disinfectants react with organic matter naturally present in water, leading to the formation of disinfection by-products (DBPs). Multi-analyte methods based on mass spectrometry (MS) are preferred to quantify multiple DBP classes at once however, most require extensive sample pre-treatment and significant resources. In this study, two analytical methods were developed for the quantification of 32 regulated and unregulated DBPs. A purge and trap (PT) coupled with gas chromatography mass spectrometry (GC-MS) method was optimized that automated sample pre-treatment and analyzed volatile and semi-volatile compounds, including trihalomethanes (THMs), iodinated trihalomethanes (I-THMs), haloacetonitriles (HANs), haloketones (HKTs) and halonitromethanes (HNMs). LOQs were between 0.02-0.4 µg/L for most DBPs except for 8 analytes that were in the low µg/L range. A second method with liquid chromatography (LC) tandem mass spectrometry (MS/MS) was developed for the quantification of 10 haloacetic acids (HAAs) with a simple clean-up and direct injection. The LC-MS/MS direct injection method has the lowest detection limits reported (0.2-0.5 µg/L). Both methods have a simple sample pre-treatment, which make it possible for routine analysis. Hyperchlorination and uniform formation conditions (UFC) formation potential tests with chlorine were evaluated with water samples containing high and low TOC. Hyperchlorination formation potential test maximized THMs and HAAs while UFC maximized HANs. Ascorbic acid was found to be an appropriate quencher for both analytical methods. Disinfected drinking water from four water utilities in Alberta, Canada were also evaluated.

While the architype room temperature ionic liquid (RTIL) based on aliphatic-primary-ammonium was discovered in 1914, it has been undeveloped until 1990s. In this three decades, RTIL composition (i.e., cations and anions) have been developed aiming at electrochemical application and green chemistry. Accordingly, bulky quaternary-ammonium, pyridine, and imidazole have nowadays been the major cations of RTILs. Currently, novel applications using the matured series of RTILs are being highly explored, and one of the promising targets is an additive for hole transport material (HTM) in perovskite solar cells (PSCs). However, although design of RTIL should be modified along each application, RTILs for the PSCs application so far has remained conventional, which limits the function. Herein, a novel RTIL comprising the architype aliphatic-primary-ammonium (i.e., n-octyl-ammonium: OA) cation and a modern Bis(Trifluoromethylsulfonyl)Imide (TFSI) anion, which are designed as an additive for hole transport layer in PSCs, was successfully synthesized for the first time. The OA cation spontaneously and densely passivated perovskite layer taking advantage of the accessibility to its cationic moiety, and simultaneously TFSI anion most likely effectively stabilized cationic radical of HTM owing to the absence of the counter cation in HTM core regime, leading to effective hole correction and thereby power conversion efficiency of 22.9% in the best cell. This work sheds light on importance of RTIL design along each application, even out of the current trend, and will help further development of various material science fields including PSCs.

Copper(I) thiocyanate (CuSCN) is one of the most robust hole-transport materials for perovskite solar cells (PSCs). However, the power conversion efficiency of CuSCN-based PSCs is low due to difficulty in crystallization of CuSCN. In this study, we focused on humidity conditions during the aging process of CuSCN-based PSCs to improve their performance. PSCs aged in humid air, i.e., at a relative humidity of 70%, exhibited better performance (efficiency; 11.3%) than those aged in lower humidity (7.3%) due to improved crystallinity of CuSCN layers. The results of the study provide insights into how to improve fabrication process of CuSCN-based PSCs for higher stability and efficiency.

A sodium chloride modification was applied where different amounts of sodium chloride was physically blended in a tin oxide colloid solution to passivate the interface between the electron transport layer (ETL) and perovskite layer and improve the performance of perovskite solar cells. Sodium chloride-modified tin oxide was utilized as the electron transport material to fabricate perovskite solar cells. It was found that sodium chloride-modified tin oxide as an ETL could considerably enhance the performance of the device compared to pristine tin oxide. The power conversion efficiency of the perovskite solar cell displayed 8.8% remarkable improvement from 18.7 ± 0.4% to 20.3 ± 0.3% on average and 9.5% improvement from 18.9 to 20.7% in champion devices because of the considerable enhancement of the fill factor when 25 mM sodium chloride-modified tin oxide as the ETL was used in comparison with pristine tin oxide.

Post-treatment of perovskite solar cells with CuSCN hole-transport layers to enhance their photovoltaic performance was investigated. Crystallinity and uniformity of CuSCN layers were improved by recrystallisation caused by oleylamine (OA) treatment. Further, the OA adsorbed on CuSCN tuned the VB edge potential and improved the hole extraction from perovskite materials. Power conversion efficiency of the CuSCN-based perovskite solar cells improved from 8.58% to 11.4%.

Halogenated solvents (e.g. chlorobenzene and chloroform) are typically used for hole-transporting materials (HTMs) in perovskite solar cells (PSCs); however, their use should be avoided as they are known to be hazardous to the environment. Herein, we synthesized a nonhalogenated-solvent-soluble, dopant-free HTM, SF62. When depositing HTMs for PSCs, SF62 could be dissolved with a nonhalogenated and green solvent, ethyl acetate. It is one of the most common organic solvents and is known to have a low environmental impact. Non-doped-SF62-based PSCs exhibited higher power-conversion efficiency (18.6%) than doped 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamino)-9,9′-spirobifluorene (Spiro-OMeTAD)-based ones (18.3%), with enhanced stability.

Tin–lead (Sn–Pb)-based perovskite solar cells (PSCs) still exhibit inferior power conversion efficiency (PCE) compared to their pure Pb counterparts because of high voltage loss (VL) and high photo...

Background During the COVID-19 pandemic, decreased volumes of stroke admissions and mechanical thrombectomy were reported. The study's objective was to examine whether subarachnoid haemorrhage (SAH) hospitalisations and ruptured aneurysm coiling interventions demonstrated similar declines. Methods We conducted a cross-sectional, retrospective, observational study across 6 continents, 37 countries and 140 comprehensive stroke centres. Patients with the diagnosis of SAH, aneurysmal SAH, ruptured aneurysm coiling interventions and COVID-19 were identified by prospective aneurysm databases or by International Classification of Diseases, 10th Revision, codes. The 3-month cumulative volume, monthly volumes for SAH hospitalisations and ruptured aneurysm coiling procedures were compared for the period before (1 year and immediately before) and during the pandemic, defined as 1 March-31 May 2020. The prior 1-year control period (1 March-31 May 2019) was obtained to account for seasonal variation. Findings There was a significant decline in SAH hospitalisations, with 2044 admissions in the 3 months immediately before and 1585 admissions during the pandemic, representing a relative decline of 22.5% (95% CI -24.3% to -20.7%, p

In recent years, LED lighting has spread rapidly and has been used in various places. Also, there has been an increase in colour printing on posters, in advertisements and on packaging using various colour for alphabetic characters and background. It is a concern that elderly people with ageing eyes which cannot read the colour characters on the colour background easily under some colour lighting. A subjective experiment was conducted on the readability of colour printing lit by different CCT lamps. The colour differences calculated by CIEDE2000 formula was smaller than the colour differences calculated by CIE76 formula under all conditions. The subject experiments showed that the readability of colour printing could not be predicted by the colour difference calculated by the CIEDE2000 formula. As a result of examination using tristimulus values, it was suggested that accurate readability evaluation can be predicted by considering colour constancy.

Lead (Pb) perovskites can be synthetically modified to form colloidal nanocrystals which exhibit remarkable optoelectronic properties in the various fields such as light-emitting devices, flexible electronics, and photodetectors. However, because of the toxicity issue of Pb, nanocrystals of Pb free such as tin (Sn)-based perovskites have got attention. In the present work, we have selected the Sn-based perovskite, Cs2SnI6, owing to the high air and thermal stability. Quantum dots of Cs2SnI6 were prepared by using two methods, namely the hot-injection method and the ultrasonic irradiation method. The difference between Cs2SnI6 particles generated by these two methods was discussed. The particles synthesized by using the hot-injection method were less than 10 nm in size and were aggregated structure due to particle tight-binding energy. On the other hand, the particles by using the ultrasonic irradiation method gave a mono-dispersed solution. The particle size was from several ten nanometers to several hundred nanometers.

Cadmium sulfide (CdS) is one of the most promising electron-transporting materials (ETMs) in perovskite solar cells (PSCs). In the present study, an ultra-thin CdS layer was prepared as the ETL usi...

Perovskite solar cells (PSCs) without a mesoporous TiO2 layer, that is, planar-type PSCs exhibit poorer cell performance as compared to PSCs with a porous TiO2 layer, owing to inefficient electron transfer from the perovskite layer to the compact TiO2 layer in the former case. The matching of the conduction band levels of perovskite and the compact TiO2 layer is thus essential for enhancing PSC performance. In this study, we demonstrate the shifting of the conduction band edge (CBE) of the compact TiO2 layer through a TiCl4 treatment, with the aim of improving PSC performance. The CBE of the compact TiO2 layer was shifted to a higher level through the TiCl4 treatment and then shifted in the opposite direction, that is, to a lower level, through a subsequent heat treatment. These shifts in the CBE were reflected in the PSC performance. The TiCl4-treated PSC showed an increase in the open-circuit voltage of more than 150 mV, as well as a decrease of 100 mV after being heated at 450 °C. On the other hand, th...

Cesium tin halide based perovskite Cs2SnI6 has been subjected to in-depth investigations owing to its potentiality toward the realization of environment benign Pb free and stable solar cells. In spite of the fact that Cs2SnI6 has been successfully utilized as an efficient hole transport material owing to its p-type semiconducting nature, however, the nature of the majority carrier is still under debate. Therefore, intrinsic properties of Cs2SnI6 have been investigated in detail to explore its potentiality as light absorber along with facile electron and hole transport. A high absorption coefficient (5 × 104 cm–1) at 700 nm indicates the penetration depth of 700 nm light to be 0.2 μm, which is comparable to conventional Pb based solar cells. Preparation of pure and CsI impurity free dense thin films with controllable thicknesses of Cs2SnI6 by the solution processable method has been reported to be difficult owing to its poor solubility. An amicable solution to circumvent such problems of Cs2SnI6 has been p...

Immersing organometal halide perovskite crystals in CH3NH3I solution converts PbI2 impurities to CH3NH3PbI3 perovskite, yielding excellent carrier transport. Hence, the power conversion efficiency ...

Frequently observed high Voc loss in tin–lead mixed perovskite solar cells is considered to be one of the serious bottle-necks in spite of the high attainable Jsc due to wide wavelength photon harvesting. An amicable solution to minimize the Voc loss up to 0.50 V has been demonstrated by introducing an n-type interface with spike structure between the absorber and electron transport layer inspired by highly efficient Cu(In,Ga)Se2 solar cells. Introduction of a conduction band offset of ∼0.15 eV with a thin phenyl-C61-butyric acid methyl ester layer (∼25 nm) on the top of perovskite absorber resulted into improved Voc of 0.75 V leading to best power conversion efficiency of 17.6%. This enhancement is attributed to the facile charge flow at the interface owing to the reduction of interfacial traps and carrier recombination with spike structure as evidenced by time-resolved photoluminescence, nanosecond transient absorption, and electrochemical impedance spectroscopy measurements.

Background Opioid-induced constipation (OIC) is the most common side effect of opioid therapy. Laxatives are usually used as a first-line treatment option for OIC. Treatment options for OIC are switching to other opioids associated with less frequent OIC, such as Fentanyl. Naldemedine is an orally active peripherally acting µ-opioid receptor antagonists that was approved in Japan from 2017 for management cancer-related OIC. The aim of this study is to investigate the relationship between Naldemedine administration and the maximum dose of oral Oxycodone which is the oral opioids used most at our hospital. Methods During June 2017 and December 2018, a total of 217 patients with cancer-related pain received Oxycodone at our institution. The first group of the patients concurrently received Naldemedine 0.2 mg daily (group A, n = 100) and the second group didn’t receive (group B, n = 117) for cancer-related OIC reduction. We compared the maximum Oxycodone dose between two groups by medical recode retrospectively. Results The median age of group A was 69 y.o. (range 20-87 y.o.), and the median age of group B was 67 y.o. (range 27-88y.o.). There was no significant difference in common patient background between group A and B. The median dose of maximum Oxycodone dose of group A was 40 mg/day (range 10-480 mg/day), and the median dose of maximum Oxycodone dose of group B was 20 mg/day (range 10-320 mg/day). There was a significant difference (Mann-Whitney U test, P Conclusions Naldemedine administration in patients with cancer-related OIC may increase the maximum dose of oral Oxycodone. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

We report the effect of the non-conjugated 5-position substituent of pyrazoline-based photosensitizers on the photophysical characteristics and performance of dye-sensitized solar cells (DSSCs). Four photosensitizers which contained different para-substituted phenyl groups (dimethylamine (6a), hexyloxy (6b), ethyl ester (6c), and no substituent (6d)) at the 5-position were synthesized. Although these substituents were not part of the conjugated π-system of the pyrazoline, their absorption maxima showed a red shift from 496 to 510 nm with increasing electron-donating ability. The same trend was observed for their electrochemical characteristics: the oxidation potentials decreased from 1.14 to 0.97 V. In terms of DSSC performance, 6a, which had a strongly electron donating substituent at the 5-position, delivered the highest short-circuit current (Jsc) of 12.3 mA cm−2, an incident photon-to-current conversion efficiency (IPCE) as high as 75%, and the best power conversion efficiency (PCE, η) of 5.7% under AM 1.5 G conditions. Further investigation with the stepped light-induced photocurrent and voltage transients (SLIM-PCV) method revealed that the steric differences between the groups at the 5-position clearly influenced the recombination reaction, resulting in the highest Voc of 636 mV in the DSSC employing 6a with the bulky dimethylamine substituent.

Dye-sensitized solar cells (DSSCs) have the potential difference between the reduction potential of the dye cation and the redox potential of electrolyte. The cobalt complex redox (Co-redox) electrolyte with the deeper redox potential is one of the candidate to avoid the energy loss for dye regeneration. However, Co-redox electrolyte could induce the fast recombination reaction at the interface between the TiO2 and the electrolyte. The recombination reaction is the reduction reaction of the redox couple with the injected electron in TiO2 and will be the causes of decreasing the open circuit voltage (V oc). To prevent the recombination reaction, the dyes may play important role as the recombination blocker on the TiO2 surfaces. For the reason, we studied first the effects of steric hindrance of the donor and the π-linker groups in donor-π-linker-acceptors (D-π-As) structured organic dyes on the recombination reaction. The steric hindrance at the donor part in the dye structure reduced the recombination reaction and increased the V oc of the DSSCs. Conversely, the small steric hindrance at the π-linker groups showed the less recombination reaction because of the higher dye coverage on the TiO2 surface. Furthermore, we studied the effects of the type of donor structure in dye structure on the DSSC performance, and compared the dyes with carbazole (MK-1), coumarin (MK-31), and triphenylamine (MK-88) and N-phenyl-carbazole (MK-90) as the typical donor structure. It found that the triphenylamine can block the recombination reaction due to the steric hindrance of the rotatable phenyl groups. We also studied the stability of the DSSCs with organic dyes. The binding strength between the dye and the TiO2 surface may affect the heat stability of the DSSCs. Carboxylic acids have generally been used as the anchoring groups for the adsorption of dyes on TiO2 surfaces. However, a phosphonic acid anchor is expected to make more stable bonding to the TiO2 surface because of its tridentate binding capability. In this study, we developed a new carbazole dye that employed a phosphonic acid anchor (MK-94) and studied the effects of the dye anchoring group on the heat stability of DSSCs at 85 °C by comparing MK-94 and MK-2 (a carbazole dye with a carboxylic acid anchoring group). In the initial, the DSSC with MK-94 exhibited a lower short circuit current (J sc) but a higher Voc than MK-2. After the heat stressing, both dyes showed the decreases in J sc and V oc but these were suppressed with MK-94. The drop of the power conversion efficiency (PCE) with MK-94 was kept within 6% after 504 h of heating. The phosphonic acid anchor was effective in extending the long-term heat stability of the DSSCs.

Stainless steel (SS) particles were demonstrated as a novel useful support for a water stationary phase in packed column supercritical fluid chromatography using a CO2 mobile phase. Separations employed flame ionization detection, and the system was operated over a range of temperatures and pressures. Retention times reproduced well with RSD values of 2.6% or less. Compared to analogous separations employing a water stationary phase coated onto a SS capillary column, the packed column method provided separations that were about 10× faster, with nearly 8-fold larger analyte retention factors, while maintaining good peak shape and comparable column efficiency. Under normal operating conditions, the packed column contains about 131 ± 4 μL/m of water phase (around a 5% m/m coating), which is over 25× greater than the capillary column and also affords it a 20-fold larger sample capacity. Several applications of the packed column system are examined, and the results indicate that it is a useful alternative to the capillary column mode, particularly where analyte loads or sample matrix interference is a concern. Given its high sample capacity, this packed column method may also be useful to explore on a more preparative scale in the future.

We analyzed the crystallization process of the CH3NH3PbI3 perovskite by observing real-time X-ray diffraction immediately after combining a PbI2 thin film with a CH3NH3I solution. A detailed analysis of the transformation kinetics demonstrated the fractal diffusion of the CH3NH3I solution into the PbI2 film. Moreover, the perovskite crystal was found to be initially oriented based on the PbI2 crystal orientation but to gradually transition to a random orientation. The fluctuating characteristics of the crystallization process of perovskites, such as fractal penetration and orientational transformation, should be controlled to allow the fabrication of high-quality perovskite crystals. The characteristic reaction dynamics observed in this study should assist in establishing reproducible fabrication processes for perovskite solar cells.

The coating properties of a novel water stationary phase used in capillary supercritical fluid chromatography were investigated. The findings confirm that increasing the length or internal diameter of the type 316 stainless-steel column used provides a linear increase in the volume of stationary phase present. Under normal operating conditions, results indicate that about 4.9 ± 0.5 μL/m of water phase is deposited uniformly inside of a typical 250 μm internal diameter 316 stainless-steel column, which translates to an area coverage of about 6.3 ± 0.5 nL/mm(2) regardless of dimension. Efforts to increase the stationary phase volume present showed that etching the stainless-steel capillary wall using hydrofluoric acid was very effective for this. For instance, after five etching cycles, this volume doubled inside of both the type 304 and the type 316 stainless-steel columns examined. This in turn doubled analyte retention, while maintaining good peak shape and column efficiency. Overall, 316 stainless-steel columns were more resistant to etching than 304 stainless-steel columns. Results indicate that this approach could be useful to employ as a means of controlling the volume of water stationary phase that can be established inside of the stainless-steel columns used with this supercritical fluid chromatography technique.

Pseudomonas aeruginosa bacteremia is associated with high morbidity and mortality in critically ill patients. In this study, we assessed risk factors for clinical failure of first definitive therapy for P. aeruginosa bacteremia in critically ill patients. All patients with P. aeruginosa bacteremia who entered the intensive care unit in Gifu University Hospital from January 2006 to December 2015 were retrospectively identified from electronic records. Risk factors associated with clinical failure of the first definitive therapy for P. aeruginosa bacteremia were analyzed by logistic regression analysis. A total of 28 patients were enrolled in the analysis. On multivariate analysis, severe burns (odds ratio [OR] = 70.9, 95% CI 2.9-1720.3; p = 0.009) and SOFA score ≥ 10 (OR = 28.5, 95% CI 1.1-754.3; p = 0.045) were significant factors in the clinical failure of first definitive therapy for P. aeruginosa bacteremia. The clinical success rate of first definitive therapy was significantly reduced in patients with these risk factors compared with those without them (p0.001). Severe burns and a SOFA score (≥ 10) were significant risk factors associated with the clinical failure of first definitive therapy for P. aeruginosa bacteremia in critically ill patients. We therefore recommend the use of therapeutic drug monitoring to optimize antibiotic dosing in these critically ill patients.

A simplified chart to determine the initial loading dose of teicoplanin (TEIC chart) for achieving the target trough concentration was developed. The aim of the present study was to evaluate the usefulness of this chart in critically ill patients.The initial loading dose and maintenance dose to achieve a target trough concentration ≥10 μg/mL on day 4 was determined using the teicoplanin TDM software and presented in a TEIC chart. The dosage of teicoplanin, including the loading dose for the first 2 days and the maintenance dose thereafter, was selected from the chart (chart method, N = 41) or calculated using TDM software (software method, N = 39).The performance rate of initial loading of teicoplanin increased from 83.0% to 100% after the TEIC chart was introduced (P = 0.016). The TEIC chart significantly reduced the time required for determining the initial loading dose compared with the use of software (1.9±0.6 min vs. 29.7±13.8 min, P0.001). No significant differences were observed in the rates of achieving a target level ≥10 μg/mL (P = 0.766).The TEIC chart enables a simple, rapid, and reliable determination of teicoplanin dosage.

The dielectric functions and optical constants of various organic-inorganic hybrid perovskite semiconductors, including HC(NH2)2PbI3, CH3NH3PbI3, CH3NH3PbBr3 and CH3NH3PbCl3, are summarized. For CH3NH3Pb(I, Br)3 alloys, the variation of the dielectric function with Br content, calculated by applying the energy shift model, is presented. This chapter also provides the optical constants of perovskite secondary phases, such as semitransparent δ-phase HC(NH2)2PbI3, PbI2 and CH3NH3I. It has been established that the dielectric functions of all the hybrid perovskite compounds can be parameterized by assuming several transition peaks calculated from the Tauc-Lorentz model. In particular, by incorporating Tauc-Lorentz peaks with very small amplitudes, the absorption coefficient spectra of the hybrid perovskites are reproduced almost perfectly in a quite wide range of α = 102–106 cm−1. In this chapter, the Tauc-Lorentz parameters obtained from the above parameterization scheme are summarized, together with the tabulated optical constants.

The dielectric functions and optical constants of various transparent conductive oxide (TCO) materials, which have been incorporated into solar cell devices, are summarized. The TCO materials described here include In2O3:Sn (ITO), In2O3:H, InZnO, SnO2:F, TiO2, and ZnO:Al (or Ga). Oxide layers such as MoOx, NiO, and WO3 are often employed to improve electronic properties at semiconductor interfaces and the optical data of these TCO layers are also described. In conventional solar cells, the free carrier absorption that occurs within the TCO layers reduces the photocurrent largely, and the characterization of the parasitic absorption within the solar cell is quite important. Accordingly, for ITO and doped ZnO layers, the variation of the dielectric function with carrier concentration is presented. Since non-doped TCO layers are widely employed as high-resistive buffer layers, the dielectric functions of non-doped In2O3, SnO2 and ZnO are also described. It is established in this chapter that all the TCO dielectric functions in the whole near-infrared/visible/ultraviolet region (1–5 eV) can be parameterized by the combined use of the Tauc-Lorentz and Drude models. For the modeling with the Tauc-Lorentz model, several transition peaks are assumed in the ultraviolet region to describe the interband transition above the band gap. In this chapter, the parameterization results for all the TCO materials are summarized, together with the tabulated optical constants.

Perovskite solar cells (PSCs) without a mesoporous TiO

Potassium-doped organometal halide perovskite solar cells (PSCs) of more than 20% power conversion efficiency (PCE) without I-V hysteresis were constructed. The crystal lattice of the organometal halide perovskite was expanded with increasing of the potassium ratio, where both absorption and photoluminescence spectra shifted to the longer wavelength, suggesting that the optical band gap decreased. In the case of the perovskite with the 5% K+, the conduction band minimum (CBM) became similar to the CBM level of the TiO2-Li. In this situation, the electron transfer barrier at the interface between TiO2-Li and the perovskite was minimised. In fact, the transient current rise at the maximum power voltages of PSCs with 5% K+ was faster than that without K+. It is concluded that stagnation-less carrier transportation could minimise the I-V hysteresis of PSCs.

Three regioregular phthalocyanines (1-3) were synthesized selectively by the cyclic tetramerization of phthalonitriles bearing a bulky diarylamine substituent at the next position of nitrile. The steric repulsion at the tetramerization of bulky phthalonitriles allowed for the selective formation of regioregular phthalocyanines as confirmed by NMR and single crystal X-ray structural analyses. The absorption spectrum of 1 substituted with di(4-tert-buthylphenyl)amine groups at the non-peripheral positions showed a non-split Q band at 764 nm, which was red-shifted by 83 nm compared with that of metal free phthalocyanine (H2Pc). The TD-DFT calculation and electrochemical studies prove that the substitution of diarylamine groups at the α positions effectively destabilizes the HOMO energy level, which causes a large red-shift of the Q band. Moreover, 1 can generate a one-electron oxidation specie through chemical oxidation. The Q band position of 2 bearing 4,4'-dimetoxyphenylamine units was further shifted by 10 nm compared with that of 1. In addition, 3 having carbazole units showed a small red-shift of the Q band relative to H2Pc. The hole-mobility of 2 in thin film was determined to be 1.1 × 10-5 cm V-1 s-1 by using a space charge limited current method. A perovskite solar cell employing 2 as a hole-transporting layer gave an efficiency of 5.1 % under standard global 100 W cm-2 AM 1.5 G illumination.

We investigated the initial photooxidation mechanism leading to reactive radical formation of polythiophene derivatives by focusing on the differences in the photochemical behaviors of photounstable poly(3-hexylthiophene) (P3HT) and photostable poly(3-octyloxythiophene) (P3OOT). Electron spin resonance measurements revealed that the [P3HT]+· (formed by oxygen doping) decayed, whereas no change was observed in the photostable [P3OOT]+· after light irradiation. Furthermore, the absorption decrease of the [P3HT]+· was suppressed by superoxide dismutase. Therefore, the oxygen dopant is superoxide, which might also initiate the oxidation of P3HT.

Potential-induced degradation (PID) in multicrystalline Si photovoltaic (PV) modules was generated by applying −1000 V from an Al plate attached on the cover glass of the module to the Si cell at 85 °C. The solar energy-to-electricity conversion efficiency of the standard Si PV module remarkably decreased from 15.9% to 0.6% after 2 h of the PID test. Increased concentration of Na species on the surface of the Si cell after the PID test was observed by secondary ion mass spectrometry (SIMS) measurement. Our results indicate that high minus voltage stress toward the Si cell causes the diffusion of metal cations, such as Na+, from the front cover glass toward the Si cell, resulting in remarkable decrease in PV performance. PID was significantly prevented by a coating of TiO2-thin film on the cover glass that suppressed the diffusion of Na+, demonstrating an attractive and promising technique for producing low-cost PID-resistant PV modules.

Aggregation of adsorbed dye molecules on TiO2 electrode typically decreases the yield of photoinduced charge separation at the dye/TiO2 interface. The decreased yield could be caused by the alternations of energy levels and/or adsorption geometry of sensitizers by the aggregation. We investigated the origin of the decreased yield for the aggregated sensitizers by employing zinc phthalocyanine-sensitized TiO2 electrode in redox-containing electrolytes. The degree of aggregation was controlled by the amount of coadsorbent, the addition of bulky molecular unit to phthalocyanine cores, and the alternation of the adsorption angle by changing the position of adsorption site. Femtosecond transient absorption measurements showed that injection yield was not significantly influenced by the aggregation but by dye adsorption angle and by the amount of dye. On the other hand, aggregation induced subnanosecond charge recombination, and the recombination seemed independent of the adsorption angle. These results appear ...