Recent discoveries have revealed a breakthrough in the photovoltaics (PVs) ! eld using
organometallic perovskites as light harvesters in the solar cell. The organometal perovskite
arrangement is self-assembled as alternate layers via a simple low-cost procedure. These
organometal perovskites promise several bene! ts not provided by the separate constituents.
This overview concentrates on implementing perovskites in PV cells such that the perovskite
layers are used as the light harvester as well as the hole-conducting component. Eliminating
hole-transport material (HTM) in this solar-cell structure avoids oxidation, reduces costs, and
provides better stability and consistent results. Aspects of HTM-free perovskite solar cells
discussed in this article include (1) depletion regions, (2) high voltages, (3) panchromatic
responses, (4) chemical modi! cations, and (5) contacts in HTM-free perovskite solar cells.
Elimination of HTM could expand possibilities to explore new interfaces in these solar
cells, while over the long term, these uniquely structured HTM-free solar cells could offer
valuable bene! ts for future PV and optoelectronics applications.