Silicon nanocrystal photovoltaic device fabricated via photolithography and its current-voltage temperature dependence

Photolithography is used as an alternative method to overcome the challenge of making anode and cathode contacts on a Si nanocrystal solar cell deposited on non-conductive substrates instead of reactive ion etching (RIE). The advantages of this method include better control of isolation mesa fabrication and the avoidance of device exposure to highly energetic particles which may cause unpredictable damage. The photovoltaic device fabricated shows an open-circuit voltage (V-oc) and a short-circuit current density (J(sc)) of 270 mV and 0.124 mA/cm(2) respectively at room temperature under one-sun illumination. Current-voltage measurements were performed at temperatures (T) from 77 K to 300 K. A model that includes recombination-generation current in the depletion region is considered to explain the observed current behaviour of the device. An ideality factor very close to 2 was calculated based on Suns-V-oc measurement, which indicates that the device is limited by recombination in the depletion region. A discrepancy was observed between the peaks (1.47 eV) in the photoluminescence spectrum and maximum V-oc (0.81 V) extrapolated from the V-oc-T relation at 0 K. This discrepancy has been attributed to the temperature dependence of the carrier lifetime in the depletion region characterized by an activation energy later defined in this article. (C) 2014 Elsevier B.V. All rights reserved.