Abstract: A method of growing a thin film comprises growing a thin film by conformally forming at least one layer over a substrate having structures extending from a surface of the substrate, whereby the or each layer is formed over the surface of the substrate and over the structures extending from the surface. The thickness of the conformal layer, or the sum of the thicknesses of the conformal layers, is at least half the average spacing of the structures, and; at least one of the height of the structures, the average spacing of the structures and the size of the smallest dimension of the structures is set so as to provide an enhanced growth rate for the or each conformal layer (compared to the growth rate over a planar substrate).

Abstract: A method includes forming elongate structures on a first substrate, such that the material composition of each elongate structure varies along its length so as to define first and second physically different sections in the elongate structures. First and second physically different devices are then defined in the elongate structures. Alternatively, the first and second physically different sections may be defined in the elongate structures after they have been fabricated. The elongate structures may be encapsulated and transferred to a second substrate. The invention provides an improved method for the formation of a circuit structure that requires first and second physically different devices to be provided on a common substrate. In particular, only one transfer step is necessary.

Abstract: A method of fabricating a device structure, comprises: forming an insulating layer (3b) over a first set of devices disposed over a substrate (3); forming one or more vias in the insulating layer; disposing a second set of devices (6) over the insulating layer, wherein devices of the second set comprise respective electrical contacts (6a) and are disposed over the insulating layer (3b) such that a side on which a contact (6a) can be accessed faces the substrate (3); and forming one or more electrical contacts between the first set of devices and the second set of devices (6) through the via(s). The second set of devices and at least one via are positioned such that one or more of the vias lies at least partially within the footprint of two devices, each belonging to a different device layer.

Abstract: A method comprises forming elongate structures (5) on a first substrate (3), such that the material composition of each elongate structure (7) varies along its length so as to define first and second physically different sections in the elongate structures. First and second physically different devices (1,2) are then defined in the elongate structures. Alternatively, the first and second physically different sections may be defined in the elongate structures after they have been fabricated. The elongate structures may be encapsulated and transferred to a second substrate (7). The invention provides an improved method for the formation of a circuit structure that requires first and second physically different devices (1,2) to be provided on a common substrate. In particular, only one transfer step is necessary.

Abstract: A method of growing a thin film comprises growing a thin film by conformally forming at least one layer over a substrate having structures extending from a surface of the substrate, whereby the or each layer is formed over the surface of the substrate and over the structures extending from the surface. The thickness of the conformal layer, or the sum of the thicknesses of the conformal layers, is at least half the average spacing of the structures, and; at least one of the height of the structures, the average spacing of the structures and the size of the smallest dimension of the structures is set so as to provide an enhanced growth rate for the or each conformal layer (compared to the growth rate over a planar substrate).

Abstract: A method includes forming elongate structures (5) on a first substrate (3), such that the material composition of each elongate structure (7) varies along its length so as to define first and second physically different sections in the elongate structures. First and second physically different devices (1, 2) are then defined in the elongate structures. Alternatively, the first and second physically different sections may be defined in the elongate structures after they have been fabricated. The elongate structures may be encapsulated and transferred to a second substrate (7). The invention provides an improved method for the formation of a circuit structure that requires first and second physically different devices (1,2) to be provided on a common substrate. In particular, only one transfer step is necessary.

Abstract: A multijunction photovoltaic structure includes a first subcell including a p-n or p-i-n junction with elongated structures; and a second subcell, arranged in tandem with the first subcell, and including a planar p-n or p-i-n junction.

Abstract: A method of encapsulating low dimensional structures comprises forming a first group (3a) of low dimensional structures (1) and a second group (3b) of low dimensional structures (1) on a first substrate. The first group (3a) of low dimensional structures (1) and the second group (3b) of low dimensional structures (1) are encapsulated in a matrix (5), with the first group (3a) of low dimensional structures (1) being encapsulated separately from the second group (3b) of low dimensional structures (1). After encapsulation, the first group (3a) of low dimensional structures (1) may be separated from the second group (3b) of low dimensional structures (1). Each group may then be processed, for example by transfer to a second substrate (7). The number of low dimensional structures in a group, and the aspect ratio of a group is defined when the low dimensional structures are formed, and can therefore be controlled more accurately than in a conventional method in which groups are defined using a patterning technique.

Abstract: A method comprises forming elongate structures (5) on a first substrate (3), such that the material composition of each elongate structure (7) varies along its length so as to define first and second physically different sections in the elongate structures. First and second physically different devices (1,2) are then defined in the elongate structures. Alternatively, the first and second physically different sections may be defined in the elongate structures after they have been fabricated. The elongate structures may be encapsulated and transferred to a second substrate (7). The invention provides an improved method for the formation of a circuit structure that requires first and second physically different devices (1,2) to be provided on a common substrate. In particular, only one transfer step is necessary.

Abstract: A method of fabricating a device structure, comprises: forming an insulating layer (3b) over a first set of devices disposed over a substrate (3); forming one or more vias in the insulating layer; disposing a second set of devices (6) over the insulating layer, wherein devices of the second set comprise respective electrical contacts (6a) and are disposed over the insulating layer (3b) such that a side on which a contact (6a) can be accessed faces the substrate (3); and forming one or more electrical contacts between the first set of devices and the second set of devices (6) through the via(s). The second set of devices and at least one via are positioned such that one or more of the vias lies at least partially within the footprint of two devices, each belonging to a different device layer.