Amorphous thin films for solar-cell applications. Final report, September 11, 1978-September 10, 1979

Abstract

LIST OF-ILLUSTRATIONS (Continued) Figure. '' 45. Wavelength dependence of surface photovoltage after "freezing in" the high-temperature surface-state electron population by heating to-130°C and then recooling to-168°C b~fore each point. The inset shows the response with time which indicates both filling

Amorphous thin films for solar-cell applications. Quarterly report No. 2, 11 December 1979-10 March 1980

“…Even though the mobility of the holes in these deep states will be low because of localization, the probability of these holes recombining with electrons is also low because of localization. In a recent report [2], we showed that the conductivity of phosphorus-doped films generally increased with increasing substrate temperature (T ) up to the S maximum temperature (%350°C) that was investigated. Figure 3-1 shows that the conductivity of boron-doped films also tends to increase with T except for s '…”

“…We have continued studies of the positive ion composition of rf discharges using the line-of-sight mass spectrometer described previously [2]. We have done studies using both the magnetron mode and the asymmetric diode mode (the intensities of clusters for x = 1 to x = 6.…”

“…This profile was obtained by secondary ion mass spectroscopy (SIMS) where the concentrations were determined by means of ion implantation standards Js c = 8.4 mA/cm and FF = 0.524); the area was 1.19 cm . Earlier work had shown that the optimum substrafe temperature range was *210° to 250°C for p-i-n devices made in an rf discharge system [2].…”

“…We will see in the next paragraph t.hat our light intensity data are completely consistent with this suggestion. Report [ 2 ] . In Fig: 6-8 we show the intensity dependence of the SPV and in the i-region; it is to be compared to that found for the initial IT0 surface (Fig.…”

“…However, a property of the Urbach t a i 1 . i~ that it has a characteristic temperature dependence of the form a = c exp (yhu/kT)(2)(3)(4)(5)(6) where y and c are constants. Even though the absorption coefficient of a-Si:H shows the exponential dependence on hu given by Eq.…”