Bandgap engineering and passivation properties of amorphous SiNx and SiNx:O:H grown by RF-magnetron sputtering

Acronym

P_SINX-BG

Consortium Coordinator

Guerra Torres, Jorge Andres

Start Date

April 1, 2017

End Date

March 31, 2018

Status

https://purl.org/pe-repo/concytec/estadoProyecto#concluido

Tipo de proyecto

https://purl.org/pe-repo/ocde/tipoProyecto#investigacionBasica

Description

Amorphous wide-bandgap semiconductors have attracted attention in the past decades. The reasons for this are twofold. First, these materials are suitable for applications in opto-electronic devices. For instance, a-SiC:H is currently a candidate to serve as photo-electrode in photo-electrochemical devices for hydrogen production [Zhu10]. Additionally, the interface between c-Si and amorphous silicon oxides/nitrides is of profound interest due to its numerous applications in microelectronics and energy conversion devices. Second, the modeling of several properties is very challenging and also they are very different from their crystalline counterpart. One important difference between amorphous and crystalline materials lay in the band-tail states. The origin of these tail states and how they merge into the extended conduction and valence band states is a still an unresolved issue. Band-to-band transitions are responsible for the main absorption and are the primary measure of the optical bandgap energy. Currently, the most prominent model for the fundamental absorption due to its easy implementation is the Tauc approach from which the Tauc-gap is calculated. However it is sensitive to both, band-tails states and the separation of the mobility edges. Furthermore it is not possible to systematically determine the fundamental absorption region from single absorption measurements due to the presence of the large band-tail states which overlap to the fundamental absorption in the typical measured spectral region. In the present one year project we attempt to produce and characterize a-SiNx and a-SiNx:O:H in the whole nitrogen composition range. Motivated by the recent publications [Gue16, Lie15] and [Sei11], we aim to tailor the optical bandgap of this material by manipulating its stoichiometry and then tune its electronic and optical properties by the incorporation of hydrogen and oxygen during the deposition process in order to improve its passivation qualities.

Keywords

Ingeniería de banda prohibida

;

Pasivación

;

SiNx

;

Pulverización catódica

Área de conocimiento

Engineering and technology

Campo OCDE

https://purl.org/pe-repo/ocde/ford#2.05.01