Determination of lifetime and surface recombination velocity of p-n junction solar cells and diodes by observing transients

Journal Article · Sun Feb 01 04:00:00 EST 1987 · IEEE Trans. Electron Devices; (United States)

DOI:https://doi.org/10.1109/T-ED.1987.22919· OSTI ID:5721395

Lindholm, F A; Liou, J J; Neugroschel, A; Jung, T W

The unified view of transient methods for the determination of recombination lifetime tau and back surface recombination velocity S presented here for silicon solar cells and diodes attempts to define limitations of existing methods and to evolve improvements. The presence of sizable junction capacitance for silicon devices under forward voltage invalidates the use of conventional open-circuit voltage decay (OCVD) and reverse recovery. This led Green to his method of compensated open-circuit voltage decay, in which the addition of an external resistor shunting the solar cell partially corrects for the presence of the junction capacitance. Setting this resistance to zero produces an electrical short-circuit current-decay method, which has the advantage of enabling determination of both tau and S. In an alternate approach, one may insert the functional dependence of the junction capacitance on forward voltage. This new method, denoted by the acronym OCVDCAP, enables the determination of tau with apparently greater accuracy than that obtained by previous methods utilizing voltage transients. But OCVDCAP has in common with the previous methods that it determines tau only and has practical utility only for determining tau of long-base devices. This means that it is useful only for thick base regions. In principle, however, it has an advantage over short-circuit current decay: it requires only pressure contacts, not ohmic contacts, and therefore may be used to determine tau after key processing steps in manufacturing.

• Research Organization: Dept. of Electrical Engineering, Univ. of Florida, Gainesville, FL 32611
• OSTI ID: 5721395
• Journal Information: IEEE Trans. Electron Devices; (United States), Journal Name: IEEE Trans. Electron Devices; (United States) Vol. ED-34:2; ISSN IETDA
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
DIRECT ENERGY CONVERTERS
ELECTRIC CONDUCTIVITY
ELECTRIC POTENTIAL
ELECTRICAL EQUIPMENT
ELECTRICAL FAULTS
ELECTRICAL PROPERTIES
ELECTRICAL TRANSIENTS
EQUIPMENT
FABRICATION
JUNCTIONS
P-N JUNCTIONS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
RECOMBINATION
RESISTORS
SEMICONDUCTOR DEVICES
SEMICONDUCTOR DIODES
SEMICONDUCTOR JUNCTIONS
SILICON SOLAR CELLS
SOLAR CELLS
SOLAR EQUIPMENT
SURFACES
TRANSIENTS
VOLTAGE DROP