Marko Topic

Marko Topic
University of Ljubljana · Faculty of Electrical Engineering

Prof. / University of Ljubljana & Colorado State University // Chairman of the ETIP-PV.eu

About

398
Publications
78,354
Reads
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7,916
Citations
Introduction
Research interests of Prof. Topic include photovoltaics, semiconductor materials, electron devices&circuits, optoelectronics, and reliability engineering. He has coauthored 180+ journal papers, 3 books and 3 patents. Within UL he is a Full Professor and the Chair of Department of Electronics. He is also an Affiliate Professor at the Colorado State University, member of Slovenian Academy of Engineering and International Academy of Engineering. Since 2014 he serves as the Chairman of ETIP PV.
Additional affiliations
September 2011 - April 2020
Colorado State University
Position
  • Professor
October 2006 - April 2020
University of Ljubljana
Position
  • Professor (Full)
Description
  • Head of the Laboratory of Photovoltaics and Optoelectronics
October 1997 - September 2002
University of Ljubljana
Position
  • Professor (Assistant)
Education
April 1994 - July 1996
University of Ljubljana
Field of study
  • Electrical Engineering

Publications

Publications (398)
Article
The complex refractive index (dielectric function) of planar CH3NH3PbI3 thin films at room temperature is investigated by variable angle spectroscopic ellipsometry and spectrophotometry. Knowledge of the complex refractive index is essential for designing photonic devices based on CH3NH3PbI3 thin films such as solar cells, light-emitting diodes, or...
Article
To increase the energy yield of installed solar photovoltaic (PV) systems, proper operation of all components should be ensured. One way to detect any misbehavior is to estimate the electric power of a PV system using data from meteorological stations or an in-situ integrated weather station to calculate the electric power of a PV system using a PV...
Article
Full-text available
In this study we analyze and discuss the optical properties of various tandem architectures: mechanically stacked (four-terminal) and monolithically integrated (two-terminal) tandem devices, consisting of a methyl ammonium lead triiodide (CH3NH3PbI3) perovskite top solar cell and a crystalline silicon bottom solar cell. We provide layer thickness o...
Article
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The status of the highest efficiency CdTe solar cells is presented in the context of comparative loss analysis among the leading technologies for single- and polycrystalline photovoltaic materials. The Shockley–Queisser limit of a single-junction cell, with acknowledgement of variations from standard conditions, is used for reference. The highest C...
Article
Photovoltaic (PV) already proves but even more promises to be massively deployed worldwide. To evaluate the performance of PV systems globally and assess risk due to different climate conditions, we propose a methodology for the global Köppen-Geiger-Photovoltaic (KGPV) climate classification that divides the globe into 12 zones with regard to the t...
Article
In the scope of solar cell characterisation, spatially resolved imaging (SRI) methods (EL, PL and LBIC) have long been a standard procedure for valuable in-depth evaluation and extraction of various spatially resolved material properties, especially those related to the electrical behaviour. While this extraction can be straightforward in the case...
Article
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In this research instrument article, the capabilities and details of a high‐throughput aging system for parallel maximum power point tracking (MPPT) of perovskite solar cells (PSCs), capable of assessing the operational stability of a large number of devices, are presented. The intention is to provide insights into the machine and the development p...
Article
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Tandem solar cells present a promising solution to overcome the Schottky–Queisser efficiency limit of single-junction solar cells. In this article, an all–thin-film tandem solar cell based on perovskite (PK) top cell and chalcopyrite Cu (In, Ga) Se2 (CIGS) bottom cell is researched. Device optical simulations are validated on the top and bottom cel...
Article
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Operators of photovoltaic (PV) systems, especially the small ones, monitor only the produced energy output, since they are not equipped with a meteorological station, or there is none in the neighbourhood. When evaluating a large number of PV systems across a region or country, access to the data due to privacy restrictions is usually very limited....
Article
Effects of temperature variation on the performance of silicon heterojunction solar cells are studied using opto-electrical simulations. It is shown that the low-temperature cell efficiency is determined by the fill factor, while at high temperatures it depends on the open-circuit voltage. Simulations revealed that the low-temperature drop in the f...
Conference Paper
Nature provides many examples of surface structures with multiple functionalities. Some of those, such as light management and self-cleaning, are of interest for increasing the efficiency of optoelectronic devices, such as OLEDs, and for adding new surface functions. However, mimicking and transferring these textures to polymers over large areas of...
Article
Accurate forecasting of yearly energy yield of photovoltaic devices under realistic operating conditions is key for numerous practical applications related to further evolution of photovoltaics. In this work we present development and validation of an energy yield model applied to planar perovskite solar cells. The model is based on the combination...
Article
Potential induced degradation (PID) is a solar cell related degradation mechanism due to high potential difference in a photovoltaic (PV) module between the solar cells and its grounded frame. This type of degradation is well known for silicon PV, however, for perovskites it has not been thoroughly researched yet. Here, we investigate the PID of pe...
Article
High selectivity of photosensors is needed for targeted biological detection. Optical interference filters are monolithically integrated with hydrogenated amorphous silicon thin film photosensors for fluorescence measurements in lab-on-chip applications using a methodology that enables customization of fluorescence detection for various application...
Article
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Optical waveguides (WGs) with all-dielectric metamaterial cladding are investigated and optimized by means of numerical simulations to increase the integration density of photonic integrated circuits (PICs). First the role of the refractive index (material platform) is studied revealing that only material platforms with a high refractive index cont...
Conference Paper
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Identifying the main factors for PV module performance losses, degradation and failures are still under research. Researchers have developed physical models to characterize the weather and the local environment where PV modules operate. , Indeed, published physical models can help to estimate PV long-term yield and degradation rates. These models h...
Conference Paper
Total solar eclipses are events that rarely occur but can highly impact the operation of electrical grids. During a few minutes, the Sun can be fully covered by the moon, blocking the sun rays towards the Earth surface. This phenomenon has a considerable effect on the electrical generation of PV systems and, depending on the level of deployment of...
Conference Paper
Full-text available
In the framework of the new H2020 project TRUST PV, the Cost Priority Number methodology, a cost-based failure modes & effect analysis method, is tailored for its application onto real-case studies during the operational phase of a PV plant. Thereby, it is possible to calculate the energetic and economic losses for each individual failure by combin...
Conference Paper
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The EU crystalline silicon (c-Si) PV manufacturing industry has faced strong foreign competition in the last decade. To strive in this competitive environment, the EU c-Si PV manufacturing industry needs to focus on highly performing c-Si PV technologies and on reducing environmental impact (lower CO2 footprint, improved sustainability, recyclabili...
Article
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A growing photovoltaic industry shows exponential deployment worldwide, and it is expected to largely contribute to the energy transition. Because PV technologies will play a major role in achieving global sustainable development and climate goals, driving more energy-efficient scenarios will require efficient approaches to evaluate systems, especi...
Article
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Hierarchical textures (combining 2D periodic large and small micro textures) as an external outcoupling solution for OLEDs have been researched, both experimentally and by optical simulations. For the case of a red bottom emitting OLED, different hierarchical textures were fabricated using laser-based methods and a replication step and applied to t...
Article
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Analyses of performance loss rates in photovoltaic (PV) systems are not yet standardized, and are typically carried out by a linear regression of the evolution of a certain performance metric (e.g., performance ratio, yield, etc.) over time. In this article, we propose a novel methodology of advanced PV system performance loss rate modeling applyin...
Article
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In monolithic tandem solar cells, current-voltage (J-V) characteristics of subcells provide invaluable information about their quality and tandem operation. However, accessing the subcell J-Vs is challenging and requires sophisticated spectral methods. In this letter, we present a customised, bichromatic LED setup (BCLED) for in-depth analysis of t...
Article
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Monolithic perovskite/silicon tandem solar cells recently surpassed the efficiency of silicon single‐junction solar cells. Most tandem cells utilize >250 µm thick, planarized float‐zone (FZ) silicon, which is not compatible with commercial production using <200 µm thick Czochralski (CZ) silicon. We demonstrate perovskite/silicon tandem cells based...
Article
The effects of defect states in doped thin-film amorphous-silicon layers (p-a-Si:H and n-a-Si:H) and at heterointerfaces of the passivated crystalline-silicon (c-Si) wafer on the performance of heterojunction silicon solar cells are investigated using optoelectrical simulations. We used a state-of-the-art numerical model of a silicon heterojunction...
Article
Full-text available
Prediction of the service lifetime of Photovoltaic (PV) modules is crucial for all PV stakeholders. PV manufacturers benefit from setting realistic warranties and researchers can improve the durability of PV materials and components in order to achieve a desired lifetime. To develop reliable predictive models, a thorough understanding of the differ...
Conference Paper
We employed numerical simulations to optimize optical performance of different photonic devices: light in-coupling in ultra-thin CIGS solar cells, light out-coupling in bottom-emitting OLEDs and reduction of optical crosstalk in silicon photonic integrated circuits.
Conference Paper
All-dielectric metamaterials can reduce the cross-talk in PICs. We present a numerical study and optimization of metamaterial cladding in silicon technology resulting in decreased minimal gap between waveguides by 53 %.
Conference Paper
Hierarchical textures are researched experimentally and by optical simulations in the role of external outcoupling solution for OLEDs. Their full outcoupling potential, limiting factors and pathways for further increase in outcoupling are addressed.
Article
Efficiency from hole-selective contacts Perovskite/silicon tandem solar cells must stabilize a perovskite material with a wide bandgap and also maintain efficient charge carrier transport. Al-Ashouri et al. stabilized a perovskite with a 1.68–electron volt bandgap with a self-assembled monolayer that acted as an efficient hole-selective contact tha...
Conference Paper
Full-text available
The interconnection of cut cells is a way to improve cell to module efficiency ratio. While this approach minimizes series resistance losses and improves module area utilization, it introduces recombination losses due to imperfect cuts. We propose two additional methods to characterize edge recombination based on multi-wavelength light beam induced...
Technical Report
Full-text available
Climate is being destabilized by greenhouse gas emissions, bringing with it more extreme weather events4. The unexpected extreme weather of today will be commonplace tomorrow, challenging the reliability of PV components. Europe is undergoing an energy transition, switching from fossil fuels and nuclear power to wind and solar PV as the primary sou...
Article
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Light emitting diodes (LEDs) have experienced rapid technological development in the past decade, making them a winning alternative to conventional light sources in many applications. LED arrays allow precise control of the desired irradiance profile in a target area by adjusting the position and output power of individual LEDs. However, despite in...
Article
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Photovoltaic monitoring data are the primary source for studying photovoltaic plant behavior. In particular, performance loss and remaining-useful-lifetime calculations rely on trustful input data. Furthermore, a regular stream of high quality is the basis for pro-active operation and management activities which ensure a smooth operation of PV plan...
Article
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Previously undiscovered failure modes in photovoltaic (PV) modules continue to emerge in field installations despite passing protocols for design qualification and quality assurance. Failure to detect these modes prior to widespread use could be attributed to the limitations of present‐day standard accelerated stress tests (ASTs), which are primari...
Conference Paper
Full-text available
Different data pipelines and statistical methods are applied to photovoltaic (PV) performance datasets to quantify the PV module degradation rate. Since the real value of degradation rate is unknown, a variety of unvalidated values has been reported in the literature. As such, the PV industry commonly treats this metric in an assumptive manner base...
Conference Paper
Full-text available
In this work, we present a comparison of Performance Loss Rate calculation methodologies based on originally 8,367 PV system datasets, primarily installed in central Europe. The system data are summarized in the Pearl PV database. Pearl PV is a European COST action aiming at improving the energy performance and reliability of PV systems. The datase...
Article
We developed a fully scalable quasi‐SPICE approach for electrical modelling of stress‐induced inhomogeneities in crystalline silicon solar cells, based on damage detected by electroluminescence imaging. We present a model of active and inactive microcracks, highlight their effects on the current‐voltage characteristic, and validate the model on a n...
Article
Liquid phase crystallized silicon solar cells on glass have recently demonstrated 15.1% efficiency using a heterojunction interdigitated back contact cell architecture and an absorber thickness of 14 μm. One of the key enabling developments was a new method to first passivate electron contact fingers with a-Si:H(i) and then locally laser fire them...
Conference Paper
Full-text available
In this work we present the application of a novel multi-step performance loss algorithm for PV systems and its practical implications. We try to better understand performance impairing effects and common occurrence patterns. The algorithm automatically detects the amount and position of breakpoints in non-linear performance ratio time series of PV...
Article
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In photovoltaic (PV) systems, energy yield is one of the essential pieces of information to the stakeholders (grid operators, maintenance operators, financial units, etc.). The amount of energy produced by a photovoltaic system in a specific time period depends on the weather conditions, including snow and dust, the actual PV modules' and inverters...
Article
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Perovskite solar cells (PSC) have shown that under laboratory conditions they can compete with established photovoltaic technologies. However, controlled laboratory measurements usually performed do not fully resemble operational conditions and field testing outdoors, with day‐night cycles, changing irradiance and temperature. In this contribution,...
Article
Random pyramids are the most widely used texture in commercial monocrystalline silicon solar cells to trap weakly absorbed photons with near-bandgap energies. There has been steady improvement in efforts to model the light-trapping performance of random pyramids, including a shift from an assumed pyramid base angle of 54.7° (ideal-random pyramids)...
Article
Full-text available
Photovoltaic (PV) systems are the cheapest source of electricity in sunny locations and nearly all European countries. However, the fast deployment of PV systems around the world is bringing uncertainty to the PV community in terms of the reliability and long-term performance of PV modules under different climatic stresses, such as irradiation, tem...
Article
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A better understanding of moisture ingress in photovoltaic modules is crucial for better predictions of their long-term behavior in the field. Current calculations and simulations of moisture uptake in photovoltaic modules are based on the Fickian diffusion model in a homogeneous material. In this article, in situ humidity measurements in four diff...
Article
Photovoltaic modules installed in the field exhibit a wide range of operating temperatures, depending on the meteorological and environmental conditions. Their temperature influences their output power and conversion efficiency. Temperature dependence is typically described as a linear function with the temperature coefficients of open-circuit volt...
Article
Full-text available
Understanding the degradation of a photovoltaic (PV) system is crucial for predicting the behaviour of a PV system or acting quickly in case of strong PV module degradation. A novel concept with Wi‐Fi devices for monitoring the substring voltages of PV modules is presented and case studies of PV modules' substring voltages during operation of the P...
Conference Paper
Liquid phase crystallized silicon (LPC-Si) solar cells on glass have demonstrated 14.2% efficiency using a heterojunction interdigitated back contact cell architecture and an absorber thickness of 13 μm. However, losses are incurred in charge collection under the majority carrier contact regions even after reducing their width to 60−120 μm. Recentl...
Article
We investigate the transport mechanism of poly-Si-based carrier-selective junctions using the two-dimensional numerical semiconductor device simulations. The detailed transport model considers the charge carrier transport through the pinholes as well as tunneling through a very thin silicon oxide simultaneously. For the verification of the simulati...
Conference Paper
Precise predictions of solar photovoltaic (PV) energy production have an important role in day-ahead planning of power grid and power plant operators since they help to improve stability and power quality of the electricity distributed. In this work, the machine learning (ML) algorithm, called as the LightGBM, is applied to the challenge of forecas...
Conference Paper
Efficiency limits of solar cells have been studied since a long time ago giving the maximal theoretical efficiency and capacity current generation for different solar photovoltaic (PV) devices, and at the same time, real solar cells are becoming more efficient. However, some gaps are still remaining to be further improved and get closer to the desi...