NOVELTY - Encapsulation structure (I) comprises a luminescent wavelength conversion material (101) comprising at least one chromophore (102) and an optically transparent polymer matrix. The luminescent wavelength conversion material is configured to encapsulate solar energy conversion device and inhibit penetration of moisture and oxygen into the solar energy conversion device.    USE - The encapsulation structure is useful for: a solar energy conversion device; improving performance of a solar energy conversion device, which contains at least one device comprising III-V or II-VI PN junction device, copper-indium-gallium-selenium thin film device, organic sensitizer device, organic thin film device, cadmium sulfide/cadmium telluride thin film device, amorphous silicon solar cell, microcrystalline silicon solar cell or crystalline silicon solar cell (all claimed); and solar cells, solar panels or photovoltaic devices.    ADVANTAGE - The encapsulation structure: enhances the solar harvesting efficiency of the solar energy conversion devices; protects cells from deleterious environmental exposure and improves efficiency in a two in one system; and provides stable long term environmental protection of device.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) an encapsulation structure (II) comprising the luminescent wavelength conversion material comprising the chromophore and the optically transparent polymer matrix and an environmental protective cover configured to inhibit penetration of moisture and oxygen into the luminescent wavelength conversion material and the solar energy conversion device, and the luminescent wavelength conversion material and the environmental protective cover are configured to encapsulate the solar energy conversion device such that light must pass through the luminescent wavelength conversion material and the environmental protective cover prior to reaching the solar energy conversion device; and    (2) improving performance of a solar energy conversion device, comprising encapsulating the device with (II).    DESCRIPTION OF DRAWING(S) - The figure illustrates an encapsulation structure, where a solar panel with several solar cell devices utilizes a luminescent wavelength conversion material to encapsulate the solar cell devices, a back sheet is underneath the light incident surface of the solar cell devices, a glass top sheet provides environmental protection and a frame holds the panel together.    Solar cell devices (100)    Luminescent wavelength conversion material (101)    Chromophore (102)    Glass top sheet (103)    Frame (107)