NOVELTY - An element comprises a substrate, at least one perovskite layer, a conductive layer, and optionally at least one additional layer, where the perovskite layer is provided on the substrate, either directly on the substrate or on additional layer positioned on the substrate, where the additional layer is different from a scaffold layer.    USE - In a device such as an electronic device or an optoelectronic device, preferably electrical-to-optical and/or optical-to-electrical transducer, where the device is photoconductors, photodiodes, solar cells, luminescent concentrator, light emitting diodes (LEDs) such as organic light emitting diodes and lasers; light sensors, pixel sensors, specialized transistors including organic transistors, inorganic transistors or hybrid transistors. The device is used in printed electronics, touch screens, display backplanes and/or large or small area flexible applications; in optoelectronic applications, RF radio, power rectifier and/or light-dependent resistors (LDRs); and in a photovoltaic cell device such as a solar cell (all claimed).    ADVANTAGE - The scaffold layer increases the surface area and therefore assists in reducing or diminishing recombination processes and therefore increases the device efficiency.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) forming an element, involving: obtaining a substrate; optionally, placing (or applying or depositing) at least one additional layer on the substrate; placing (or applying or depositing) at least one perovskite layer on a substrate or on at least one additional layer; and placing (or applying or depositing) a conductive layer on top of the perovskite layer or on at least one additional layer;    (2) a heterojunction comprising the element;    (3) a device implementing or comprising the element or comprising an active component consisting of a substrate, at least one perovskite layer, a conductive layer, and optionally at least one additional layer; and    (4) a photovoltaic cell comprising a substrate, at least one perovskite layer, a conductive layer, and optionally at least one additional layer.