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Background Erdafitinib, a pan-fibroblast growth factor receptor (FGFR) tyrosine kinase inhibitor, was shown to be clinically active and tolerable in patients with advanced urothelial carcinoma and prespecified FGFR alterations in the primary analysis of the BLC2001 study at median 11 months of follow-up. We aimed to assess the long-term efficacy and safety of the selected regimen of erdafitinib determined in the initial part of the study. Methods The open-label, non-comparator, phase 2, BLC2001 study was done at 126 medical centres in 14 countries across Asia, Europe, and North America. Eligible patients were aged 18 years or older with locally advanced and unresectable or metastatic urothelial carcinoma, at least one prespecified FGFR alteration, an Eastern Cooperative Oncology Group performance status of 0–2, and progressive disease after receiving at least one systemic chemotherapy or within 12 months of neoadjuvant or adjuvant chemotherapy or were ineligible for cisplatin. The selected regimen determined in the initial part of the study was continuous once daily 8 mg/day oral erdafitinib in 28-day cycles, with provision for pharmacodynamically guided uptitration to 9 mg/day (8 mg/day UpT). The primary endpoint was investigator-assessed confirmed objective response rate according to Response Evaluation Criteria In Solid Tumors version 1.1. Efficacy and safety were analysed in all treated patients who received at least one dose of erdafitinib. This is the final analysis of this study. This study is registered with ClinicalTrials.gov, NCT02365597. Findings Between May 25, 2015, and Aug 9, 2018, 2328 patients were screened, of whom 212 were enrolled and 101 were treated with the selected erdafitinib 8 mg/day UpT regimen. The data cutoff date for this analysis was Aug 9, 2019. Median efficacy follow-up was 24·0 months (IQR 22·7–26·6). The investigator-assessed objective response rate for patients treated with the selected erdafitinib regimen was 40 (40%; 95% CI 30–49

Incomplete light absorption makes effective light-trapping (LT) crucial for realising higher short-circuit current densities (Jsc) in liquid-phase crystallised silicon (LPC Si) thin-film solar cells on glass superstrate. Through a systematic investigation, this research aims to develop, optimise and incorporate different LT features (improving both light-coupling and light-trapping) into 10 um thin solar cells crystallised by a continuous wave diode laser on borosilicate glass. The features include anti-reflection (AR) layers, back surface reflectors (BSRs), Si texturing and glass texturing. Potential Jsc estimated from optical characterisation is used to optimise different LT features. The optimised features are then incorporated into active solar cells and the actual Jsc is derived from external quantum efficiency measurement.An AR foil is used on the front air-side of the glass to improve broadband light-coupling. With the foil, the Jsc is increased by 1.1 mA/cm2 (5.5% enhancement). BSRs are evaluated to enhance long wavelengths absorption. The optimum BSR is found by combining silver nanoparticles, white paint and the AR foil, with Jsc of 23.3 mA/cm2 (18.9% enhancement).Si texturing is done by wet chemical etching to increase long wavelengths absorption. Porous mask texturing, ammonium fluoride and potassium hydroxide-based solutions (KOH) are evaluated. KOH-based texturing is the best method, with Jsc up to 25.4 mA/cm2 (24.5% enhancement), when combined with white paint BSR and AR foil. Glass is mechanically abraded to enhance broadband absorption. Following abrasion, prolonged glass etching resulting in surface roughness below 600 nm is required to enable a successful crystallisation of the Si films on the textured glass. The films exhibit large grains of several hundred micrometers in width and up to centimeters in length, similar to the films crystallised on planar glass. A significant broadband absorption enhancement is achieved, but electrical degradation

We develop an assimilation method of high horizontal resolution sea surface temperature data, provided from the Moderate Resolution Imaging Spectroradiometer (MODIS-SST) sensors boarded on the Aqua and Terra satellites operated by National Aeronautics and Space Administration (NASA), focusing on the reproducibility of the Kuroshio front variations south of Japan in February 2010. Major concerns associated with the development are (1) negative temperature bias due to the cloud effects, and (2) the representation of error covariance for detection of highly variable phenomena. We treat them by utilizing an advanced data assimilation method allowing use of spatiotemporally varying error covariance: the Local Ensemble Transformation Kalman Filter (LETKF). It is found that the quality control, by comparing the model forecast variable with the MODIS-SST data, is useful to remove the negative temperature bias and results in the mean negative bias within -0.4 °C. The additional assimilation of MODIS-SST enhances spatial variability of analysis SST over 50 km to 25 km scales. The ensemble spread variance is effectively utilized for excluding the erroneous temperature data from the assimilation process.

Liquid phase crystallised silicon on glass (LPCSG) is a promising solar cell technology using high-quality polycrystalline silicon thin films to produce low-cost solar modules. In this work, a line-focused continuous-wave diode laser is used to melt and recrystallise 10 micron thick silicon films on borosilicate glass. Different intermediate layers between the glass and the silicon are assessed for their suitability for such cells. SiOx, SiNx and SiCx are tested either as single films or in multilayer stacks with regard to optical properties as an anti-reflection coating (ARC), wettability, silicon crystal quality, diffusion properties and device performance.SiOx is found to be optically indistinguishable from the glass, providing no anti-reflective benefit. SiCx is limited to thin (~20 nm) films due to parasitic absorbance. Combining thin SiCx with a thin Si-side SiOx layer creates an acceptable ARC. SiNx provides the best ARC.SiCx layers, either alone or in stacks with SiOx, are found to provide the best wettability, allowing the largest range of laser parameters for crystallisation without silicon dewetting. SiOx and SiNx allow a smaller, but sufficient process range. Large crystal grains, several millimetres in length, are formed after crystallisation with all intermediate layer options. The density of twin grain-boundaries is found to be dependent upon intermediate layer class, with single layer SiOx causing the lowest density, followed by SiCx-based layers, then SiNx-based layers.SiOx is found to be the best barrier against boron diffusion from the borosilicate glass, limiting unintentional doping to <1e16 cm-3. Diffusion of nitrogen and carbon into the silicon from SiNx and SiCx layers occurs, causing concentrations of up to 1e19 cm-3. Iron concentration up to 1e17 cm- 3 is found in several silicon films after crystallisation, regardless of intermediate layer.Solar cell efficiency remains below 4 % when SiNx or SiCx intermediate layers are in contact with the

The purpose of this thesis is to improve electronic quality of polycrystalline silicon thin film solar cells by plasma hydrogen passivation. This hydrogen passivation study is conducted on two different polycrystalline silicon solar cells, which are SPC (Solid Phase Crystalline) and LPC (Liquid Phase Crystalline) silicon solar cells. Firstly, hydrogen passivation on SPC silicon solar cells is focused on finding impact of process parameters on thicker cells (3, 4, and 5 um) than baseline 2 um cell. It is discovered that higher process temperature improves open-circuit voltage most and the impact increases as cell is getting thicker. Process time and plasma power does not have significant effect on improving open-circuit voltage. These findings can be applied to optimise thicker SPC silicon solar cells which promises higher short-circuit current. Secondly, hydrogen passivation on LPC silicon solar cells is studied. LPC solar cells are thicker (10 um) than SPC cells and have less crystallographic defects. These differences require development of different hydrogen passivation. In LPC cells, both process temperature and process time have substantial impacts on increasing open-circuit voltage but plasma power does not have impacts on it. Additionally, improvements which are associated to n=1 and n=2 are also investigated through Suns-Voc data. Not only n=1 related defects but also n=2 related defects are well-passivated by higher process temperature and longer process time.

It is a challenge for academics and industrialists to develop solar cells with high energy conversion efficiency and low manufacturing cost. Polycrystalline silicon thin-film solar cells on glass is a competitive photovoltaic technology in that it combines the advantages of the mature crystalline silicon technology with low material usage and large-area monolithic construction typical for the thin-film approach. The focus of this thesis is on n-type polycrystalline silicon thin-film solar cells on glass prepared by electron-beam evaporation and solid-phase crystallization. It can be categorized into two parts. The first part introduces the study on material and optimization of cell structure, as well as investigation on the post-deposition treatments. Important issues are addressed, such as absorber doping control via diffused back surface field, influence of emitter doping and thickness on cell performance, influence of absorber doping on cell performance, the effect of RTA temperature on cell performance, the effect of hydrogen passivation temperature on cell performance, and the defects induced by the hydrogen passivation. The second part is a systematic study on development of a silicon nanostructure in polycrystalline silicon thin film solar cells. The silicon nanostructure is fabricated by metal-assisted wet chemical etching. Silver nanoparticles by thermal annealing of a thin silver film are used as metal catalyst. The silicon nanostructure demonstrates excellent light trapping, which is a very critical issue for thin-film solar cells. The silicon nanostructure can be passivated by atomic layer deposited aluminium oxide, in which way the electrical property of the film is improved. In the end of this thesis, 90% short-circuit current density enhancement has been achieved by application of the silicon nanostructure, resulting in the highest current density of 23.31 mA/cm2. A highest open-circuit voltage of 503 mV has been achieved for polycrystalline silicon t

Dielectric scattering structures are a promising way of trapping light in solar cells. Titanium dioxide is a particularly attractive candidate material because of its high refractive index and ability to be deposited on a finished solar cell. Here, we present an experimental demonstration of photocurrent enhancement in thin film recrystallised silicon solar cells using TiO2 pillar arrays fabricated on the rear of the cells using nanoimprint lithography. A short circuit current enhancement of 19% is measured experimentally, and excellent agreement with numerical simulations is obtained. We show numerically that by replacing the Ag capping present on the cells with a detached rear Ag back reflector, the enhancement could reach 37%.

The focus of this thesis is on the optimisation of metallisation for 10 µm thick laser-crystallised polycrystalline silicon thin film solar cells with glass (LPCSG). These cells originate from the crystalline silicon on glass (CSG) technology. University of New South Wales has been developing new processes for deposition (by e-beam evaporation) and crystallisation (by a line focus diode laser) of thin Si films. There still remain several engineering challenges in the cell such as the high fractions of power loss from existing metallisation scheme and the degradation of open circuit voltage (V_oc) and fill factor (FF). The thesis contributes to LPCSG cell development by optimising the metallisation scheme and investigating the benefits of selectively doped absorber contacts. The first section of the thesis focuses on optimisation of the point-contact metallisation scheme. The parameters such as size and number of contact openings are optimised by the fractional power loss modelling. This contact optimisation of metallisation scheme results in an improved FF, from 56% to 69.9%. In the second section, the thesis develops and applies a method for creating a locally diffused boron doped region under the absorber contacts to prevent degradation of V_oc in the completed devices as well as to improve contact resistance. The work in the thesis demonstrates to be ascribed to the interaction between the aluminium and lightly doped p-type silicon after heat treatment for contact-bake. One way of eliminating the degradation is selective doping of the absorber contacts. The result shows that it eliminates the degradation of both V_oc and FF. However, it can introduce localised ohmic shunt was found in the cell. Dark lock-in thermography images confirm that there is a significant ohmic shunt near the openings which are patterned for the selective boron doping. Reducing the size of the openings helps to minimise the shunt, which results in V_oc of 510 mV and J_sc of 23 mA/〖cm〗^2.La

This thesis is divided into three main chapters, covering Flash Lamp Annealing (FLA)experiments in Chapter 1, FLA thermal and structural simulations in Chapter 2, andPhotoluminescence (PL) Imaging in Chapter 3.The first and second chapters aim to gauge the feasibility of replacing the existing beltfurnace Rapid Thermal Process (RTP) with FLA for Silicon (Si) films on a glasssubstrate that have been crystallised by Solid Phase Crystallisation (SPC). Theexperimental work gives us insight into the maximum stress that the film can handleduring the FLA process, as well as giving us a baseline for parameters to investigate inany future experiments. It is found that FLA with 3ms pulses and 20ms pulses are notsuitable replacements for the current RTP setup because significant damage to the filmis observed at lower pulse energy densities than that required to achieve an adequatelevel of annealing. The modelling in chapter 2 predicts that the magnitude of the stresswill increase with increasing pulse duration, making successful annealing at longerpulse durations unlikely.Equipment capable of producing pulse durations above 80 milliseconds, and capable ofheating the Si film to temperatures between 1350°C to 1400°C does not currently exist.For this reason these pulse durations have not been investigated, but a basic designguide on how longer pulse durations could be produced is provided.The third chapter concentrates on PL Imaging of thin film Silicon Solar cells on glass.PL Imaging allows a noncontact method of characterising the quality of the Silicon filmat various stages of the production process. Through PL Imaging, it was discovered thatthere is a large variation in material quality from sample to sample, as well as within thesame sample. It is also found that the PL signal is wavelength dependent, and throughmodelling of cell parameters in PC1D, we can use this wavelength dependence to infera minority carrier lifetime on low quality Si material.

Thin film photovoltaics (PV) can potentially have a lower manufacturing cost by minimising the amount of a semiconductor material used to fabricate devices. Thin-film solar cells are typically only a few micrometres thick, while crystalline Silicon (c-Si) wafer solar cells are 180 - 300 micrometers thick. Incident light is not fully absorbed in such thin-film layers, resulting in lower energy conversion efficiency compared to c-Si wafer solar cells. Therefore, effective light trapping is required to realise commercially-viable thin film cells, particularly for indirect-band-gap semiconductors such as crystalline silicon. An emerging method for light trapping in thin film solar cells is the use of metallic nanostructures that support surface plasmons. Plasmon-enhanced light absorption is shown to increase cell photocurrent in many types of solar cells. This thesis presents the author’s results on plasmonic polycrystalline silicon (poly-Si) thin film solar cells. It can be categorised into three parts, which are the optimum cell’s surface condition for nanoparticle (NP) fabrication, optimisation of Ag NP fabrication process to enhance energy conversion efficiency and a wet-etching method for re-using metallised polycrystalline silicon thin film solar cells after NP deposition. The first part (Chapter 3.2) introduces the optimum surface condition for silver NPs. NPs are formed on Si film, a native SiO2 and a thermal SiO2 layer, and absorption, scattering cross section and potential short-circuit current density are compared for varying surface conditions. The sample with NPs on the thermal SiO2 layer shows better absorption at 500 – 700 nm wavelength range, whilst the sample with NPs on the native SiO2 and with NPs directly on Si show higher absorption at greater than 700 nm. The sample with NPs on the native SiO2 layer indicates 62.5% potential short circuit current density enhancement, which is 0.7% and 12% higher enhancement than that of the sample with NPs directly

Plasmonic effects on metal particles are a promising way of trapping light in solar cells. We experimentally demonstrate enhanced absorptance in thin silicon using metal nanoparticle arrays in conjunction with a rear mirror. The nanoimprint process is a fast and scaleable method for producing nanoscale light trapping structures. Incorporating both nanoparticle arrays and a rear mirror leads to a substantial increase in absorptance, due to resonant interference effects. We numerically simulate a planar Ag mirror deposited onto a planarized sol-gel silicon dioxide (SiO2) layer, and show the enhancement could reach 53%. We also find that a conformal Ag mirror deposited on a sputtered SiO2 layer could give similar enhancement. Experimentally, we derive predicted Jsc enhancements of up to 2.8 mA/cm2 from absorptance measurements. The experimental results show good qualitative agreement with numerical simulations as the thickness is increased, with clear evidence of absorptance enhancement via a Fabry-Perot resonance effect.

The effect of the silver nanoparticle size distribution on the performance of plasmonic polycrystalline Si thin-film solar cells is studied. Monodisperse particle arrays are fabricated using nanoimprint lithography. Multidispersed particle arrays are fabricated using thermal evaporation followed by annealing. The short-circuit current enhancement for the cells without a back reflector is 24% and 18% with the multidisperse array and the monodispersed array, respectively. For the cells with a back reflector, the current enhancement increases to 34% and 30%, respectively, compared with 13% enhancement due to the reflector alone. Better performance of multidisperse Ag nanoparticle arrays is attributed to a broader scattering cross section of the array owing to a broad particle size distribution and a higher nanoparticle coverage.

For thin-film crystalline Si solar cells on glass, metallisation is the key to converting what is otherwise a large-area diode, into a true photovoltaic device. The goal of metallisation is to produce devices with as high efficiencies and as little parasitic losses as possible. This is the inspiration here, where the metallisation of crystallised Si material deposited by plasma-enhanced chemical vapour deposition (PECVD) is of particular interest. The metallisation investigated is based on an interdigitated scheme, where the positive and negative electrodes of the device form a comb-like structure on the cell surface. This unique structure allows for a variety of investigations to take place aimed at both improving understanding of the scheme, and exploring methods to further increase efficiencies of metallised devices. The results are structured into three main parts. In the first part, power loss formulas, both absolute and normalised, were derived for the interdigitated-on-glass device structure. This allows for the characterisation and identification of the various resistive and shadow losses associated with metallisation. Optimal metallisation patterns were then realised by minimising these power losses. The second part involves metallisation itself, where device fabrication, sidewall formation, and the impact of thermal annealing were investigated. High-rate PECVD (>200 nm/min) was introduced as a means of combating one of the main drawbacks of PECVD. An efficiency of 5.9 % was obtained on this material - the first reported result for high-rate PECVD poly-Si thin-films on glass. In the third part, the concept of cell tabbing and interconnection using wire-bonding was developed. Both tabbing of individual cells and interconnection to form mini-modules were found to significantly reduce series resistance, boosting fill factors and efficiencies of metallised devices. An 8.05 % efficient individual cell and an 8.28 % two-cell mini-module were fabricated using this

A large area cw diode laser is utilised in this thesis to develop three new processes to improve the efficiency and reduce the cost of silicon thin-film solar cells made on glass substrates. The first is a defect annealing process which replaces a belt furnace anneal for the removal of crystallographic defects and activation of dopants in solid-phase crystallised silicon. The highest substrate temperature required during the process sequence is reduced from 960C to 620C, which opens the door to the use of cheaper glass substrates. A peak 1-sun voltage of 492 mV is achieved on planar samples, which is an improvement of 30 mV over the belt furnace process. The films are shown to be partly recrystallised during the process, significantly improving the material quality of the melted section while retaining the dopant profile within the un-melted section. Completed devices are shown to match the performance of the optimised belt furnace process. The second is a complete laser crystallisation process applied to thick a-Si films. Here the film is molten across the entire thickness, and a regime is found whereby long linear grains are formed by continuous growth with the previous crystallised region acting as a seed for the newly crystallising material. Grains up to millimetres in length and hundreds of microns in width have been grown with virtually zero detectable intra-grain defects. A rear diffused emitter isused to create a p-n junction, which produces 1-sun voltages as high as 539 mV. IQE measurements show that the glass-side of the films is very well passivated and that the diffusion length is much longer than the device thickness. Cells up to 7.01% efficiency have been demonstrated without light trapping or optimisation of many of the key processes. The third new process is large area solid-state diffusionusing a diode laser to drive in spin-on dopants. This process has been used to form a junction and demonstrated some of the highest voltages on the diode laser cry

A novel method, snow globe coating, is found to show significant enhancement of the short circuit current JSC (35%) when applied as a scattering back reflector for polycrystalline silicon thin-film solar cells. The coating is formed from high refractive index titania particles without containing binder and gives close to 100% reflectance for wavelengths above 400 nm. Snow globe coating is a physicochemical coating method executable in pH neutral media. The mild conditions of this process make this method applicable to many different types of solar cells.

Polycrystalline silicon (poly-Si) thin-film solar cell is one of promising technologies for low cost photovoltaic electricity generation. Such cells are made of a ~2 μm thin poly-Si diode structure formed on a low-cost glass superstrate. Because the glass cannot withstand prolonged treatments at temperatures much higher than its critical points, to obtain poly-Si material with acceptable electronic quality the precursor a-Si thin films with cell structure are typically crystallised at the standard temperature of 600°C for 20 hrs. This lengthy annealing time leading to a large thermal budget and low throughput diminishes attractiveness of poly-Si thin film on glass solar cells. Moreover, this standard solid-phase crystallisation (SPC) results in high defect density in poly-Si, which is a major performance limiting factor. Therefore, improving poly-Si quality is the main objective of the SPC study. The focus of this thesis is SPC of Si thin-film solar cells on glass deposited by electron-beam (E-beam) evaporation, plasma enhanced chemical vapour deposition (PECVD), and their combination (Hybrid). The study aims to achieve the following goals: (i) to develop better understanding of SPC stages, including incubation, nucleation and crystal growth, for Si films with the solar cell structure; (ii) to identify how these stages, the resulting poly-Si thin-film quality and solar cells performance depend on SPC conditions, (iii) to find out how the film structure, i.e. dopant concentrations and the layer thicknesses, affects the crystallisation kinetics and the resulting cell performance, (iv) to examine the effects of pre-annealing conditions on the crystallisation kinetics and the resulting cell performance.The SPC of PECVD, Hybrid and E-beam poly-Si solar cell structures is studied by four characterisation techniques at different temperatures of 600, 640 and 680°C. The random nucleation in Si thin-film solar cell structures is demonstrated by transmission electron micr

Photovoltaics is likely to become one of the world major energy sources in the future providing it is able to meet demands of a significantly lower production cost. It requires cheap materials, equipment and processes on the one hand, and high energy conversion efficiency on the other hand. The focus of this thesis is on polycrystalline silicon thin-film solar cells on glass prepared by electron-beam evaporation and solid-phase crystallisation – an emerging technology with a potential to meet the requirements. It combines the advantages of the mature crystalline silicon technology with low material usage and large- area monolithic construction typical for the thin-film approach. Importantly, it replaces an expensive and complicated Si film fabrication technique, plasma enhanced chemical vapour deposition, with a much simpler and cheaper electron beam evaporation.This thesis presents the author’s research results on evaporated polycrystalline silicon cells. It covers a wide range of important topics: silicon material preparation, cell fabrication, glass substrate texturing and back surface reflectors. It can be categorised into two parts. The first part introduces the process of fabricating a metallised photovoltaic device from silicon feedstock. Important issues are addressed, such as doping control, comparison of p-type cells and n-type cells, sample wrinkling, contamination protection, metallisation of planar cells and textured cells, etc. The second part is a systematic study on light trapping, a very critical issue for thin-film silicon solar cells. It is found that glass texturing is hardly compatible with evaporated cells due to the defects associated with the micro-columnar structures introduced by the texture topography. In the case when no suitable texturing can be used, an efficient back surface reflector is extremely important as the only means to enhance the light-trapping. The best back surface reflector found by the author is a combined struc

Significant photocurrent enhancement has been achieved for evaporated solid-phase-crystallized polycrystalline siliconthin-filmsolar cells on glass, due to light trapping provided by Agnanoparticles located on the rear siliconsurface of the cells. This configuration takes advantage of the high scattering cross-section and coupling efficiency of rear-located particles formed directly on the optically dense silicon layer. We report short-circuit current enhancement of 29% due to Agnanoparticles, increasing to 38% when combined with a detached back surface reflector. Compared to conventional light trapping schemes for these cells, this method achieves 1/3 higher short-circuit current.

The cost of photovoltaic electricity needs to be significantly reduced in order to achieve a high electricity market penetration. Thin-film solar cells have good potential to achieve such cost savings though (i) large-area deposition onto low-cost foreign substrates, (ii) more streamlined processing, (iii) monolithic cell interconnection, and very efficient use of the expensive semiconductor material. Polycrystalline silicon (poly-Si) on glass is a promising technology for the cost-effective large volume production of PV modules since it (i) makes use of an abundant raw material, (ii) is non-toxic, (iii) does not suffer from light-induced degradation, and (iv) does not rely on TCO layers. Usually plasma enhanced chemical vapour deposition (PECVD) is used for the layer formation. This thesis explores the use of e-beam evaporation as deposition method since it is potentially much faster and cheaper than PECVD. The resulting solar cells are referred to as EVA (from EVAporation).Two inherent shunting mechanisms in EVA cells are demonstrated to be shunting through sub-micron sized pinholes when the back electrode is deposited and shunting between the emitter and the absorber layer at the glass-side electrode. Through the improved understanding of these shunting mechanisms it was possible to develop a suitable metallisation scheme for EVA cells using an aligned deposition of emitter and back surface field line contacts and a specially developed shunt mitigation etching technique. For the first time appreciable efficiencies of up to 5.2% were demonstrated on this material. It was also shown that only very lightly doped absorber layers can lead to the required high short-circuit currents in EVA cells. The resulting cells are currently completely limited by space charge region recombination occurring with comparatively low ideality factors of only ~ 1.4This thesis also demonstrates the usefulness of Jsc-Suns measurements and investigates optical loss mechanisms in the curren