The upper limit for the efficiency of organic solar cells: will organic photovoltaics be able to compete with traditional solar cells?

status: publishe

Modeling of nanostructured photovoltaics: the network model and the effective medium model

status: publishe

Accuracy of defect distributions measured by bias dependent admittance spectroscopy on thin film solar cells

Thin film solar cells have achieved efficiencies up to 20%. Despite these excellent results, the understanding of the underlying mechanisms and the influence of defects on their performance is still incomplete. In thin film solar cells often defect level distributions are present rather than discrete defects. These distributions can be calculated from admittance measurements, however several assumptions are needed which hinder an exact defect density determination. By performing the measurements under different bias voltage conditions the accuracy of the method can be improved and assessed. This is illustrated with measurements on a flexible thin film Cu(In,Ga)Se2- based (CIGS) solar cell

Modelling thin film solar cells with graded band gap

This paper discusses how graded absorber structures in CIGS-based solar cell can be studied using the numerical simulation tool SCAPS. A model will be built for an AVANCIS solar cell with double grading which is produced with the laboratory line process. We will first discuss how literature and measurement data should be used to start the buildup of the model and afterwards give an illustration how the model then still has to be optimized. We will draw special attention to the consequences of a graded structure on the model. Moreover, we will show how one can discern the real grading benefit by comparison with a uniform reference model

Information and Communication Technologies, Market Rigidities and Growth: Implications for EU Policies

The renewed Lisbon strategy puts special emphasis on the potential role that Information and Communication Technologies can play in meeting the challenges of boosting growth, competitiveness and cohesion throughout the EU. There is also a general understanding among policy makers that investment of this kind and its related economic benefits can only materialize if labour, capital, product and service markets are flexible enough to facilitate ICT investment and the re-organisation of economic activities. This paper provides evidence of the influence of market rigidities on the propensity to invest in ICT and on the economic return of ICT investment in a number of EU countries, and in the US and Japan. We provide evidence that indicates that market rigidities deter ICT investment and lower the impact of ICT on GDP growth by considering a number of indicators reflecting barriers to business creation and the degree of market regulation in labour and capital markets. These results are invariant, even when other potential determinants of ICT investments and ICT contribution to GDP growth such as the degree of specialisation in ICT-producing industries, past ICT investment, business cycles conditions and a measure of trade openness are controlled for. The paper provides a number of policy implications, most notably, regarding the role played by structural reforms in promoting both ICT adoption and setting the best framework conditions for ICT impact on GDP growth. While the renewed EU Lisbon strategy of economic reforms is badly needed to increase EU growth potential, we show here that this strategy is also needed to promote technological change in the EU economy.Information and Communication Technologies, ICT, Growth, European Union, Lisbon Strategy