  Selective extraction of photo-generated carriers is a fundamental challenge
in solar cells which is usually achieved through junctions with the associated
doping as well as band offset differences. In this context, here we propose a
new paradigm for selective extraction for majority carriers through novel usage
of the programmable charge trap which comprises of Oxide-Nitride-Oxide (ONO)
stack and has the primary function of holding electrically injected charge.
Through detailed numerical simulations, here we show that such a charge trap
with an additional metal contact can (i) compensate for efficiency loss due to
sub-optimal passivation and sub-optimal hole selectivity in homojunction as
well as transition metal oxide-based heterojunction solar cells and (ii) can
also function as a standalone hole selection scheme. The proposed scheme, with
its easy integration and the capability of programmable compensation of
performance loss, is of interest to the photovoltaic community.
