A Cost-Effective Growth of SiOx Thin Films by Reactive Sputtering : Photoluminescence Tuning

• We present a new cost-effective method to produce substoichiometric SiO2 thin films by means of a simple sputter-coater operated at a base pressure of 1 x 10(-3) mbar. During sputtering air is introduced through a fine valve so that the sputtering gas is a mixture of air/Ar. High-resolution electron microscopy shows the formation of amorphous SiOx thin films for the as-deposited samples. The index x approaches 1 when the ratio of the partial pressure of air/Ar tends to 0.1. On the other hand, pure silica is formed when the ratio of the partial pressure of air/Ar approaches 0.5. The films in the as-deposited state show intense green yellow photoluminescence. This fades away with short annealing under air at 950 degrees C. If on the other hand, prolonged annealing is performed under Argon atmosphere at 1000 degrees C, red-infrared photoluminescence is recorded due to the formation of Si nanocrystals embedded in SiO2. This simple method could be suitable for the production of thin SiOx films with embedded nanocrystals for optoelectronic or photovoltaic applications.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

Si Nanocrystals

Photoluminescence

Thin Films

Silicon

Optoelectronics

Defects

Silicon Oxide

Photovoltaics

Physics

Fysik

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