  Most traditional semiconductor materials are based on the control of doping
densities to create junctions and thereby functional and efficient electronic
and optoelectronic devices. The technology development for halide perovskites
had initially only rarely made use of the concept of electronic doping of the
perovskite layer and instead employed a variety of different contact materials
to create functionality. Only recently, intentional, or unintentional doping of
the perovskite layer is more frequently invoked as an important factor
explaining differences in photovoltaic or optoelectronic performance in certain
devices. Here we use numerical simulations to study the influence of doping and
photodoping on photoluminescence quantum yield as well as other device relevant
metrics. We find that doping can improve the photoluminescence quantum yield by
making radiative recombination faster. This effect can benefit or harm
photovoltaic performance given that the improvement of photoluminescence
quantum efficiency and open-circuit voltage is accompanied by a reduction of
the diffusion length. This reduction will eventually lead to inefficient
carrier collection at high doping densities. The photovoltaic performance might
improve at an optimum doping density which depends on a range of factors such
as the mobilities of the different layers and the ratio of the capture cross
sections for electrons and holes.
