Strategies for realizing high-efficiency silicon heterojunction solar cells

Silicon heterojunction (SHJ) solar cells have achieved a record efficiency of 26.81% in a front/back-contacted (FBC) configuration. Moreover, thanks to their advantageous high V_OC and good infrared response, SHJ solar cells can be further combined with wide bandgap perovskite cells forming tandem devices to enable efficiencies well...

Modulated surface texturing of temporary Al foils substrates for high-efficiency thin-film, flexible solar cells

In this work we focus on texturing Al substrate in order to employ the modulated surface texturing approach for thin-film, flexible, micromorph solar cells. We deployed two different methods to induce micro-craters in Al foil, i) bare Al etching by KOH and ii) AZO sacrificial layer etched in KOH. After modelling the etching kinetics of KOH on...

A Pragmatic Approach to Impairment Awareness in Optical Networks

The points-of-presence of optical networks are interconnected by photonic paths capable of carrying Terabits of data. However, signals along those photonic paths accumulate transmission impairments and thus can be unreadable at the receiver if the accumulated impairments are too high. Our contributions in this paper are three-fold: (1) we...

Size control, quantum confinement, and oxidation kinetics of silicon nanocrystals synthesized at a high rate by expanding thermal plasma

The growth mechanism of silicon nanocrystals (Si NCs) synthesized at a high rate by means of expanding thermal plasma chemical vapor deposition technique are studied in this letter. A bimodal Gaussian size distribution is revealed from the high-resolution transmission electron microscopy images, and routes to reduce the unwanted large Si NCs are...

Raman Study of Laser Induced Heating Effects in Free-Standing Silicon Nanocrystals

This paper demonstrates that free-standing silicon nanocrystals (Si NCs) have significantly different thermal conductivity properties compared to Si NCs embedded in a host matrix. The temperatures of Si NCs under laser illumination have been determined by measuring the ratio of the Anti-Stokes to Stokes intensities of the first order Si–Si...

Quadruple-junction thin-film silicon-based solar cells with high open-circuit voltage

Enhancing the driving field for plasmonic nanoparticles in thin-film solar cells

The scattering cross-section of a plasmonic nanoparticle is proportional to the intensity of the electric field that drives the plasmon resonance. In this work we determine the driving field pattern throughout a complete thin-film silicon solar cell. Our simulations reveal that by tuning of the thicknesses of silicon and transparent conductive...

Micro-textures for efficient light trapping and improved electrical performance in thin-film nanocrystalline silicon solar cells

Comparing performance and situation awareness in USAR unit tasks in a virtual and real environment

A convenient way to test Urban Search And Rescue (USAR) robots would be in virtual environments (VEs). Evaluations in VEs are generally accepted as alternative for real scenarios. There are obvious differences between operation in a real and virtual environment. Nonetheless, the current experiment showed no significant differences in situation...

Revealing unexpected effects of rescue robots’ team-membership in a virtual environment

In urban search and rescue (USAR) situations resources are limited and workload is high. Robots that act as team players instead of tools could help in these situations. A Virtual Reality (VR) experiment was set up to test if team performance of a human-robot team increases when the robot act as such a team player. Three robot settings were...

Improved light trapping in microcrystalline silicon solar cells by plasmonic back reflector with broad angular scattering and low parasitic absorption

We show experimentally that the photocurrent of thin-film hydrogenated microcrystalline silicon (?c-Si:H) solar cells can be enhanced by 4.5?mA/cm2 with a plasmonic back reflector (BR). The light trapping performance is improved using plasmonic BR with broader angular scattering and lower parasitic absorption loss through tuning the size of...

Ultrahigh throughput plasma processing of free standing silicon nanocrystals with lognormal size distribution

We demonstrate a method for synthesizing free standing silicon nanocrystals in an argon/silane gas mixture by using a remote expanding thermal plasma. Transmission electron microscopy and Raman spectroscopy measurements reveal that the distribution has a bimodal shape consisting of two distinct groups of small and large silicon nanocrystals with...

Optical model for multilayer structures with coherent, partly coherent and incoherent layers

We present a novel approach for modeling the reflectance, transmittance and absorption depth profile of thin-film multilayer structures such as solar cells. Our model is based on the net-radiation method adapted for coherent calculations and is highly flexible while using a simple algorithm. We demonstrate that as a result arbitrary multilayer...

The role of oxide interlayers in back reflector configurations for amorphous silicon solar cells

Thin oxide interlayers are commonly added to the back reflector of thin-film silicon solar cells to increase their current. To gain more insight in the enhancement mechanism, we tested different back reflector designs consisting of aluminium-doped zinc oxide (ZnO:Al) and/or hydrogenated silicon oxide (SiOx:H) interlayers with different metals ...

Effect of ion bombardment on the a-Si:H based surface passivation of c-Si surfaces

We have found that controlled Ar ion bombardment enhances the degradation of a-Si:H based surface passivation of c-Si surfaces. The decrease in the level of surface passivation is found to be independent on the ion kinetic energy (7–70 eV), but linearly proportional to the ion flux (6×1014–6×1015?ions?cm?2?s?1). This result suggests that the ion...

Multiple wireless protocol advertising system, enabling automatic access selection and local services

We examined efficiency within wireless access options for mobile devices and discovered that a classic pitfall is revisited. As with the proliferation of services in incumbents’ portfolios, leading to a number of coexisting so-called ‘stove-pipes’, we see an isomorphic phenomenon evolving in multimodal mobile devices, leading to an inefficient...