vai al contenuto della pagina vai al menu di navigazione
 

Nanocrystal Formation in Silicon Oxy-Nitride Films for Photovoltaic Applications: Optical and Electrical Properties

In the present contribution we investigated the properties of one Si based oxides (SiOxNy) which has recently attracted a lot of attention in different and innovative applications, like CO2 capture, waveguides for nanosensors, and as conductive oxide.

Authors

Martina Perani, Nils Brinkmann, Adnan Hammud, Daniela Cavalcoli, and Barbara Terheiden

Abstract

Silicon heterojunction solar cells (SHJ) consist of thin amorphous silicon layers deposited on crystalline silicon wafers. This design enables the highest energy conversion efficiency (around 25%) among the Si based solar cells.

The substitution of amoprphous Si with Si based oxides could even increase the conversion efficiency of SHJ cells. In the present contribution we investigated the properties of one Si based oxides (SiOxNy) which has recently attracted a lot of attention in different and innovative applications, like CO2 capture, waveguides for nanosensors, and as conductive oxide. In the present contribution we studied thin films of nanocrystalline SiOxNy in view of their application in silicon heterojunction solar cells.

In particular, the formation of the nanocrystals and their effects on the electrical and optical properties of the films are investigated. The role of the oxygen content on the properties of the layers is clarified as well.

The obtained layers show very high conductivity (44 S/cm), low activation energy (1.85 meV) and high Tauc gap (2.5 eV), promising features for their application in photovoltaics.

The (top) figures report an example of optical transmission spectra (left) and atomic force micrograph (right) of the SiOxNy layer. The (bottom) fig shows a cross-section secondary electron micrograph of the SiOxNy deposited on Si and the sketch shows its role within the SHJ cell.

J. Phys. Chem. C, 2015, 119 (24), pp 13907–13914

http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.5b02286

Authors from UNIBO-DIFA: Martina Perani, Daniela Cavalcoli