• PDF / 854,527 Bytes
• 12 Pages / 414.72 x 648 pts Page_size
• 47 Downloads / 264 Views

DOWNLOAD

REPORT

---

DOPING AND ALLOYING OF HYDROGENATED AMORPHOUS GERMANIUM FILMS PREPARED BY DC-MAGNETRON SPUTTERING T. DRUSEDAU* **, A. ANNEN*, and B. SCHRODER*, * FB Physik der Universitit Kaiserslautern, Postfach 3049, W-6750 Kaiserslautem, Germany, ** Feodor Lynen - Fellow of the Alexander von Humboldt - Foundation, present address: Harvard University, Division of Applied Sciences, Cambridge, MA 02138 ABSTRACT In this paper we present a detailed study of doping and alloying effects in a-Ge:H due to the incorporation of phosphorus, nitrogen, oxygen, boron, carbon and silicon. The film characterization was performed by means of quantitative analysis , optical absorption in the band and subband range and conductivity measurements. N and 0 were found to form donor states resulting in an increase of the dark conductivity up to five orders of magnitude. The maximum value of OD=0. 3 (Qcm)"1 has been obtained by N-doping of about 1 at% solid phase concentration, which exceeds the effect of P doping. B doping causes a decrease of the dark conductivity to a minimum of 10-6 (i2cm)-I at 150 ppm solid phase concentration. Addition of Si and C up to concentrations of about 5 at% does not influence the subgap absorption, where best values of E 0