Carrier lifetimes and influence of in-grown defects in N-B Co-doped 6H-SiC

• The thick N-B co-doped epilayers were grown by the fast sublimation growth method and the depth-resolved carrier lifetimes have been investigated by means of the free-carrier absorption (FCA) decay under perpendicular probe-pump measurement geometry. In some samples, we optically reveal in-grown carbon inclusions and polycrystalline defects of substantial concentration and show that these defects slow down excess carrier lifetime and prevent donor-acceptor pair photo luminescence (DAP PL). A pronounced electron lifetime reduction when injection level approaches the doping level was observed. It is caused by diffusion driven non-radiative recombination. However, the influence of surface recombination is small and insignificant at 300 K.

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

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

Nyckelord

Energy gap

Light emission

Silicon carbide

Solar cells

Diffusion driven

Donor-acceptor pairs

Electron lifetime

Free carrier absorption

Measurement geometry

Non-radiative recombinations

Sublimation growth

Surface recombinations

Carrier lifetime

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