X-ray detectors are made by growing CsPbI.sub.3 on a treated surface of a conductive layer. Growth is controlled by increasing solvent concentration in the atmosphere in which the growth occurs. Columnar crystals grown in a plurality of wells extend between conductive surfaces at least one of which is pixelated to produce a columnar detector array.

A method of fabricating an ionic crystal includes providing a single crystal substrate of an ionic crystal material is provided. A patterned mask is applied over the single crystal substrate A growth solution is introduced over the single crystal substrate. The growth solution includes precursors for epitaxial growth of the ionic crystal material on the single crystal substrate such that epitaxial crystals grow over time through pattern openings in the patterned mask into a crystal structure with one or more morphologies.

A method of fabricating an ionic crystal includes providing a single crystal substrate of an ionic crystal material is provided. A patterned mask is applied over the single crystal substrate A growth solution is introduced over the single crystal substrate. The growth solution includes precursors for epitaxial growth of the ionic crystal material on the single crystal substrate such that epitaxial crystals grow over time through pattern openings in the patterned mask into a crystal structure with one or more morphologies.

In accordance with a method of forming a halide perovskite thin film, a first halide perovskite material is chosen from which a halide perovskite thin film is to be formed. An epitaxial substrate formed from a second halide perovskite material is also chosen. The halide perovskite thin film is epitaxially formed on the substrate from the first halide perovskite material. The substrate is chosen such that the halide perovskite thin film formed on the substrate has a selected value of at least one property. The property is selected from the group including crystal structure stability, charge carrier mobility and band gap.

A method of forming a perovskite superlattice includes providing a single crystal substrate. The single crystal substrate is exposed to a precursor composition having ions and molecules therein of which a perovskite is composed to thereby form a perovskite superlattice on the single crystal substrate. The perovskite superlattice includes at least one series of layers having alternating inorganic slabs and organic spacers. The single crystal substrate and the inorganic slabs have lattice constants that differ from one another by less than a prescribed amount.

A method of forming a perovskite superlattice includes providing a single crystal substrate. The single crystal substrate is exposed to a precursor composition having ions and molecules therein of which a perovskite is composed to thereby form a perovskite superlattice on the single crystal substrate. The perovskite superlattice includes at least one series of layers having alternating inorganic slabs and organic spacers. The single crystal substrate and the inorganic slabs have lattice constants that differ from one another by less than a prescribed amount.

A space-confined temperature gradient induced monolithic (STIM) integration growth apparatus capable of adjusting a thickness of a perovskite single crystal and growing a large-area perovskite single crystal may include an upper housing including a storage space in which a perovskite precursor solution is stored, a lower housing coupled to a lower part of the upper housing, and a temperature control device disposed under the lower housing. The lower housing may include a first frame, a second frame disposed to be spaced apart from the first frame, and a spacer that is disposed between the first frame and the second frame and that partitions a growth space for a perovskite single crystal seed.

A space-confined temperature gradient induced monolithic (STIM) integration growth apparatus capable of adjusting a thickness of a perovskite single crystal and growing a large-area perovskite single crystal may include an upper housing including a storage space in which a perovskite precursor solution is stored, a lower housing coupled to a lower part of the upper housing, and a temperature control device disposed under the lower housing. The lower housing may include a first frame, a second frame disposed to be spaced apart from the first frame, and a spacer that is disposed between the first frame and the second frame and that partitions a growth space for a perovskite single crystal seed.

Embodiments relate to methods of forming a halide perovskite crystal. The method involves dispersing a halide perovskite material exhibiting a perovskite crystallographic lattice into a solution. The solution can include amine and a volatile solvent. The method involves forming a metastable intermediate state via amine molecules inserting into the perovskite crystallographic lattice. The method involves transitioning the perovskite material to a photo-sensitive phase via escape of the amine molecules from the perovskite crystallographic lattice. The method involves transitioning the metastable intermediate state to a halide perovskite crystal film.

Embodiments relate to methods of forming a halide perovskite crystal. The method involves dispersing a halide perovskite material exhibiting a perovskite crystallographic lattice into a solution. The solution can include amine and a volatile solvent. The method involves forming a metastable intermediate state via amine molecules inserting into the perovskite crystallographic lattice. The method involves transitioning the perovskite material to a photo-sensitive phase via escape of the amine molecules from the perovskite crystallographic lattice. The method involves transitioning the metastable intermediate state to a halide perovskite crystal film.