We report results from a national project about impurities in high performance multicrystalline silicon: Contamination sources, transport routes, interaction with crystal defects and impact on solar cell efficiency parameters. Several ingots were produced lab scale furnace. Growth parameters crucible types varied, purity quartz crucibles compared to novel silicon nitride crucibles. The material was characterized by range of methods including FTIR, GDMS, NAA, EBSD, dislocation etching,...

Hydrogen (H) is thought to be strongly involved in the light and elevated temperature-induced degradation observed predominantly p-type silicon wafers, but nature of defect or defects this process currently unknown. We have used infrared (IR) spectroscopy detect vibrational signatures due H–B, H–Ga, H2*(C) thin, hydrogenated, multicrystalline wafers after increasing optical path length by preparation polishing edges a stack wafers. The concentrations H–B H–Ga acceptor complexes are reduced...

Operation and maintenance (O&M) is needed to limit losses caused by soiling degradation in PV power plants, but accurate estimates of both mechanisms are necessary inform decisions made the O&M team. In present work, we propose a novel performance metric, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\boldsymbol{CP}}{{\boldsymbol{R}}}_{{\boldsymbol{soiling}}}$</tex-math></inline-formula> , that can be...

Oxidation-induced stacking fault rings in polished Cz silicon samples before and after thermal wet oxidation are investigated by use of photoluminescence imaging. Currently the standard procedure for OSF ring detection is to expose a toxic preferential etchant, e.g. Wright solution, oxidation. This solution primarily attacks regions with faults, allowing visual inspection. Samples from seed end p-type ingots resistivities approximately 1 Ohm-cm were measured PL imaging process. Subsequently,...

In this paper we present a novel method for measuring temperature dependent lifetime images with high spatial resolution using photoconductance calibrated photoluminescence (PL) imaging. order to achieve this, PL are recorded at various temperatures by implementing stage into commercial, steady state imaging setup. Carrier then calculated from the detected intensity, based on quasi-steady calibration measurements performed same that used images. By analysing carrier data as function of...

Owing to the well-known temperature dependence of photovoltaic (PV) module performance, it is important correct performance ratio with respect temperature. In this study, coefficients given by manufacturer for three different PV cell technologies are compared experimentally obtained a park situated in southern Norway. Three irradiance estimation methods used calculate these experimental coefficients. The results show that they can differ significantly from ones provided datasheet all...

The influence of phosphorus diffusion gettering on recombination at grain boundaries has been studied in a commercially cast high performance multicrystalline silicon block. Wafers from four different heights have with resolution photoluminescence-imaging. was linescans perpendicular to the bounadary interest. change activity after correlated orientation measured by electron backscatter diffraction and classified according Brandon criterion. relative carrier lifetime depends height cast, is...

In this paper we present a novel approach to investigate the influence of non-uniformity in minority carrier lifetime c-Si wafers on solar cell efficiency. By using combination one-dimensional device modelling (cmd-PC1D 6) and finite element circuit (Griddler 2) are able simulate total IV characteristics based input from images. With suitable regarding optical properties, doping profiles, recombination behaviour sheet resistance passivated metallized surfaces involved combined model can be...

Sequential degradation measurements have been performed on passivated high performance multicrystalline silicon wafers, first at room temperature under low intensity illumination followed by a higher an elevated temperature. The presence of two main mechanisms, affecting the lifetime different conditions has demonstrated, namely, well-studied light induced caused boron-oxygen-complexes and less understood degradation. Light is limiting recombination path when fully activated, but...

This work demonstrates a novel technique for calibrating temperature dependent photoluminescence (PL) images of silicon wafers with high accuracy. The PL signal is calibrated using heat-controlled photoconductance (PC) stage integrated into the imaging system. PC measured in true steady state condition and used to determine calibration constant under same illumination as image, thus providing high-precision calibration. results robust method important physical parameters, such minority...

We present a method for extracting local recombination rates from photoluminescence images of double side passivated wafers, using simulations lateral charge carrier diffusion in two dimensions. By fitting the simulated lifetime map with calibrated image, profiles bulk and at grain boundaries (GBs) can be extracted. This used to quantify GB velocity even if concentration is simultaneously affected by multiple GBs. High performance multicrystalline wafers commercially cast ingot low impurity...

This paper comprehends a systematic study of the prospects for an unambiguous assessment presence two separate defects in silicon samples analyzed by temperature- and injection-dependent lifetime spectroscopy (LS). A large number datasets are generated simulating then fitted to single-defect model. We have categorized outcome four categories: (i) low overall fit quality thus likely combination defects, (ii) high dominance one involved defect, (iii) because symmetry effects model, (iv) but no...

In this paper we have used a sequential measurement routine to separate and evaluate the effects of two dominant mechanisms for degradation carrier lifetime silicon wafers: Boron-oxygen related light induced (BO-LID) elevated temperature (LeTID). Wafers from different heights in high performance multicrystalline brick first been illuminated at room fully activate BO-LID process wafers, followed by an annealing more detrimental recombination sites causing LeTID. By isolating LeTID way hope...

Accurate performance modeling of utility-scale PV plants is crucial for reducing the risk investment, as well improving operations and maintenance. In spite much research, precise rate at which degrade still not known. This article uses a well-known methodology calculating degradation rates to assess impact climate on long-term performance. The RdTools analytic approach used perform comparative case study two with same setup almost identical technology yet located in distinct climates. A...

The rate at which silicon solar cells and wafers degrade regenerate when subjected to light elevated temperatures (LeTID) is known depend on the minority carrier concentration. In this article, we utilize spatial differences in of degradation regeneration multicrystalline estimate dependence these rates We apply relation obtained from investigations a model describing temporal LeTID defect evolution. With updated evolving charge density during considered, obtain drastically improved fit...

Several field studies comparing modules based on Elkem Solar Silicon® (ESS®) cells with reference non-compensated virgin polysilicon show that the compensated ESS®modules outperform comparable installed capacity under certain operating conditions. At high temperatures and irradiation conditions silicon produce more energy than modules. In order to increase understanding of observed effect are studied at different by means IV-characteristics as well quantum efficiencies. Quantum efficiency...

Silicon solar modules typically operate at a higher temperature than the 25 °C used for standard testing, and coefficient (TC) therefore might have significant impact on field performance. In this paper dependent behavior of compensated Si cells has been simulated using PC1Dmod6.2, combination physical models which include effect both compensation doping. The simulations were based experimental input measured two high performance multicrystalline ingots similar resistivity ∼1.3 Ωcm, as well...

Silicon (Si) wafers cut from an industrially grown ingot were subjected to phosphorus (P) gettering. The gettering was performed by coating the with spin-on sources containing five different P concentrations and are a diffusion process at temperature of 900 °C for 380 seconds. Thereafter, selected lifetime measurements. effect on distribution metallic impurities near wafer surface determined in parallel performing secondary ion mass spectrometry measurements neighbouring same processes. A...

The cutoff frequency and current from an organic thin-film transistor (OTFT) are strongly dependent on the length to some extent uniformity of channel. Reducing channel can improve OTFT performance with increase in frequency. Picosecond laser ablation printed Ag electrodes, compatible roll-to-roll fabrication, has been investigated. threshold was found be similar for wavelengths tested: 515 nm 1030 nm. Short channels could opened both after light annealing at 70 °C 140 °C. lightly cured...

The minority carrier lifetime is a crucial material parameter in silicon (Si) wafers for use solar cell applications, and precise measurements of as function the excess concentration (injection level) high importance. In this paper we present method extracting injection-dependent data with spatial resolution, without need advanced time-resolved camera detection systems. This enables investigations single grains, grain boundaries structural defects spatially non-uniform lifetime, such...

Minority carrier lifetime degradation in crystalline silicon wafers is a topic of high technological importance and have been subject to an active research effort the latest years. Recently, annealing dark shown cause regeneration over time, similarly much-studied light elevated temperature induced (LeTID). In this work, we study compare subsequent behavior during illuminated as well p-type HPMC-Si with different resistivity compensation level. During both annealing, find that extent lower...