Method of manufacturing thin film devices

A method of concomitantly manufacturing at least two thin-film photovoltaic devices, the method comprising:

• applying a liquid perovskite precursor on a first surface of a first planar substrate;
• positioning a second surface of a second planar substrate proximate to the first surface of the first planar substrate to provide parallelly disposed adjacent substrates, such that the first surface and the second surface are in contact with the liquid perovskite precursor;
• sliding the parallelly disposed adjacent substrates over one another such that the liquid perovskite precursor is drawn over the first surface and the second surface, which when the parallelly disposed adjacent substrates slide passed one another, provide a first coating on a first surface and a second coating on the second surface;
• drying the first coating and the second coating to provide a first film and a second film;
• and
• fabricating a charge transport layer on each of the first film and the second film;
• fabricating an electrode on the charge transport layers,
• thereby concomitantly manufacturing at least two thin-film photovoltaic devices.