I-V characterization of tunnel diodes and multijunction solar cells

This paper discusses common difficulties in measuring tunnel diodes and sets a special focus on devices consisting of tunnel diodes and solar cells, such as multijunction solar cells. The resulting theoretical current-voltage (I-V) characteristics of tunnel diodes and solar cells when measured via four-wire techniques are calculated and compared with experimentally measured I-V curves. Solutions to overcome the measurement difficulties are provided, and a method to infer the maximum tunneling current density of tunnel diodes in a device with solar cells is discussed. This paper also describes how the elsewhere-observed ostensible hysteresis with multijunction solar cells is caused by the measurement setup or by large internal series resistances.