High Voltage Photovoltaic Devices for Autonomous Solar-to-Fuel Applications

In this dissertation, a framework is presented for the development of high voltage multijunction photovoltaic (PV) devices. Specifically, wireless silicon-based monolithically integrated 2-terminal multijuction PV devices are investigated. Such devices can be used in autonomous solar-to-fuel synthesis systems, as well as other innovative...

The fundamental operation mechanisms of nc-SiO_X≥0:H based tunnel recombination junctions revealed

Two terminal multi-junction (MJ) photovoltaic (PV) devices are well established concepts to increase the solar-to-electrical power conversion in reference to single PV junctions. In multi-junction PV devices two consecutive sub-cells are interconnected using a tunnel recombination junction (TRJ) in which the light excited holes of one sub...

Spectroscopic review of hydrogenated, carbonated and oxygenated group IV alloys

Semiconductors based on group IV elements are widely used in the fields of micro-electronics, optics and photonics. The group IV alloys are processed using plasma enhanced chemical vapor deposition and its opto-electrical properties are a result of the material composition and structure. Infrared and Raman spectroscopy are complementary and...

Application of metal, metal-oxide, and silicon-oxide based intermediate reflective layers for current matching in autonomous high-voltage multijunction photovoltaic devices

A logical next step for achieving a cost price reduction per Watt peak of photovoltaics (PV) is multijunction PV devices. In two-terminal multijunction PV devices, the photo-current generated in each subcell should be matched. Intermediate reflective layers (IRLs) are widely employed in multijunction devices to increase reflection at the...

DIrect Sunlight into CO conversion

In this abstract an overview is presented of research performed in the DISCO project, on the development of a silicon-based high voltage multijunction device for autonomous solar to fuel applications.'

Improved PECVD processed hydrogenated germanium films through temperature induced densification

Amorphous and nano-crystalline germanium is of potential interest for a wide range of electronic, optical, opto-electronic and photovoltaic applications. In this work the influence of deposition temperature on hydrogenated germanium (Ge:H) films was characterized, using over 200 Ge:H and over 70 SiGe:H films. The demonstrated temperature...

The optical performance of random and periodic textured mono crystalline silicon surfaces for photovoltaic applications

Surface textures that result in high optical yields are crucial for high efficiency photovoltaic (PV) devices. In this work three different texturing approaches are presented that result in smooth concave structures devoid of sharp features. Such features can sustain the crack-free growth of device quality nano- to poly-crystalline materials...

PECVD Processing of low bandgap-energy amorphous hydrogenated germanium-tin (a-GeSn:H) films for opto-electronic applications

An alloy based on the group IV elements germanium and tin has the potential of yielding an earth-abundant low bandgap energy semiconductor material with applications in the fields of micro-electronics, optics, photonics and photovoltaics. In this work, the first steps towards the plasma enhanced chemical vapour deposition (PECVD) processing of a...

Opto-Electrical Properties of Group IV Alloys: The Inherent Challenges of Processing Hydrogenated Germanium

In this paper the opto-electrical nature of hydrogenated group IV alloys with optical bandgap energies ranging from 1.0 eV up to 2.3 eV are studied. The fundamental physical principles that determine the relation between the bandgap and the structural characteristics such as material density, elemental composition, void fraction and...

Infrared analysis of catalytic CO2 reduction in hydrogenated germanium

The oxidation and carbisation kinetics of porous amorphous and nano-crystalline hydrogenated germanium (a-Ge:H and nc-Ge:H) films exposed to ambient air and deionized water have been studied using vibration modes observed by infrared spectroscopy. Based on infrared analysis, a two-step process of first oxidation by water and secondly carbisation...

The Relation Between Precursor Gas Flows,Thickness Dependent Material Phases, andOpto-Electrical Properties of Dopeda/nc-SiOX≥0:H Films

Doped layers are a determining factor for the performance of photovoltaic devices such as silicon heterojunction and thin film silicon solar cells. The material properties of doped hydrogenated amorphous/nanocrystalline silicon-oxide (a/nc-SiO X≥0 :H) films processed by plasma-enhanced chemical vapor deposition generally exhibit a tradeoff...

Advanced textured monocrystalline silicon substrates with high optical scattering yields and low electrical recombination losses for supporting crack-free nano- to poly-crystalline film growth

Crystalline silicon tandem devices with perovskites, CIGS, and nanocrystalline silicon, as well as the TOPCon design, are incompatible with the conventional pyramidal surface texture of silicon. This is a result of crack formation in nano to polycrystalline growth on large sharp surface features. In this work, three texturing approaches are...

The impact of processing conditions and post-deposition oxidation on the opto-electrical properties of hydrogenated amorphous and nano-crystalline Germanium films

Low-cost multijunction photovoltaic devices are the next step in the solar energy revolution. Adding a bottom junction with a low bandgap energy material through plasma enhanced chemical vapor deposition (PECVD) processing could potentially provide a low-cost boost in conversion efficiency. A logical candidate for this low bandgap material is...

Policy options for sustainable protein consumption in the Netherlands

The Master's programme Industrial Ecology is jointly organised by Leiden University and Delft University of Technology.