Modellierung und Simulation semi-transparenter organischer Solarzellen

Diese Arbeit beschäftigt sich mit den elektrischen und den optischen Eigenschaften semi-transparenter organischer Solarzellen. Hierzu wird ein optoelektronisches Simulationsmodell entwickelt und die simulierten Ergebnisse mit experimentell bestimmten Daten verglichen. Neben dem Wirkungsgrad der Solarzellen liegt ein besonderes Augenmerk auf den Farbeigenschaften des durch die semi-transparenten Solarzellen transmittierten Lichts

Understanding the angle-independent photon harvesting in organic homo-tandem solar cells

The effective device photo current of organic tandem solar cells is independent of the angle of light incidence up to 65°. This feature renders these devices particularly suitable for stationary applications where they receive mainly indirect light. In a combined experimental and simulative study, we develop a fundamental understanding of the causal absorption and charge generation mechanisms in organic homo-tandem solar cells. A 3-terminal tandem device architecture is used to measure the optoelectronic properties of both subcells individually. The analysis of the angle dependent external quantum efficiencies of the subcells and the tandem device reveal an internal balancing of the wavelength dependent subcell currents elucidating the low sensitivity of the tandem device properties on the angle of incidence

Illumination angle and layer thickness influence on the photo current generation in organic solar cells: A combined simulative and experimental study

In most future organic photovoltaic applications, such as fixed roof installations, facade or clothing integration, the solar cells will face the sun under varying angles. By a combined simulative and experimental study, we investigate the mutual interdependencies of the angle of light incidence, the absorber layer thickness and the photon harvesting efficiency within a typical organic photovoltaic device. For thin absorber layers, we find a steady decrease of the effective photocurrent towards increasing angles. For 90-140 nm thick absorber layers, however, we observe an effective photocurrent enhancement, exhibiting a maximum yield at angles of incidence of about 50°. Both effects mainly originate from the angle-dependent spatial broadening of the optical interference pattern inside the solar cell and a shift of the absorption maximum away from the metal electrode

Modellierung und Simulation semi-transparenter organischer Solarzellen

In this work the electrical and optical properties of semi-transparent organic solar cells are investigated. For this purpose an optoelectronic simulation model is developed and simulated results and experimental data are compared to each other. Besides the efficiency of the solar cells this work puts a special emphasis on the color properties of the light, which is transmitted through the semi-transmitted solar cells

Compensation for RC-effects in organic photodiodes with large sheet resistances

Abstract-Transient measurements on semiconductor devices are distorted by parasitic effects due to the geometric capacitance of the device and the impedance of the attached measurement circuit. Together they form an RC-circuit. Ideally, the transient decay of the pulse response generated by such an RC-circuit follows an exponential function. We investigate the differential equations of the case of an oblong rectangular photodiode with significant sheet resistance of one electrode. We find that under a specific illumination profile the ideal RC-decay can be obtained which is an useful result for RC-compensation in organic photodiodes