New methods of measuring photoelectric parameters of silicon
Members of group:
Research activity:
In the last years we have developed new methods of measurement of the
photoelectric parameters of silicon wafers used for solar cell fabrication.
The methods are based on compensation of the a.c. photovoltage, and are used
to determine the diffusion length and the minority charge lifetime in the
substrate.
One of the methods permits to determine the photoelectric parameters of
wafer without conductive electrodes. In particular, it can be used for
wafers packed in hermetically sealed polyethylene parcels. This allows to
avoid its contamination during the measurements. The method can also be used to
test the diffusion length in the wafers at intermediate stages of fabrication
of solar cells and other semiconductor devices. This enables to reject
nonconditional wafers in the process of fabrication and thus decrease the
cost of the device. The method can be easily automatized.
The methods were tested on silicon solar cells irradiated by fast particles.
Selected publications:
- O.G. Koshelev, S.A. Lagutkin and T.B. Pleskacheva. The use of heavily doped
silicon in a bolometer having a separated target. Sov.J.Opt.Technol.
52, 517 (1985).
- O.G. Koshelev, T.B. Pleskacheva and L.N. Khitrova. Transmission spectra of
thin doped layers of silicon on a high-resistance substrate in the long IR
region. Opt. and Spectrosc. 60, 466 (1986).
- O.G. Koshelev and T.B. Pleskacheva. Determination of the electrophysical
parameters of a highly doped silicon layer on a high-resistance substrate from
transmission of the layer for long-wave infrared radiation.
Moscow University Physics Bulletin 43, N 1, 82 (1988).
- V.A. Morozova, O.G. Koshelev and V.V. Ostroborodova. Peculiarities of the
photoelectric properties of highly pure silicon.
Vestnik Moskovskogo Universiteta. Ser. Fiz., astron. 31, 92 (1990).
- O.G. Koshelev and I.V. Mikhailov. A phase method for defining the life
time of minority charge carriers in the base of photoconverter.
Appl.Sol.Energy 29, N 4, 11 (1993).
- O.G. Koshelev, V.A. Morozova, E.Yu. Barinova, G.M. Grigorieva and E.H.
Tkacheva. Measurement of short lifetimes of minority charge carriers in
silicon solar cells irradiated by fast electrons.
Moscow University Physics Bulletin 48, N 4, 80 (1993).
- O.G. Koshelev and V.A. Morozova. A method of determination of
photoelectrical properties of minority charge carriers in substrates of
diode structures. Patent of Russia N 2019890 (1994).
- O.G. Koshelev, V.A. Morozova. A nondestructive method for measuring the
photoelectric parameters of wafers with p-n-junctions.
Solid-State Electronics 39, 1379 (1996).
Physics of Semiconductors division