Window inserts comprising ultraviolet-absorbing and visibly transparent photovoltaic devices producing on-board electricity

Abstract

In one aspect, window inserts are described herein, which can modulate transmission of electromagnetic radiation through a window and can be self-powered. In some embodiments, a window insert comprises a photovoltaic device, the photovoltaic device including a photosensitive layer having peak absorption between 250 nm and 450 nm and an average transmittance of at least 50 percent in the visible region of the electromagnetic spectrum.

1 . A method of modulating the transmission of electromagnetic radiation through a window or facade comprising:
 arranging a window insert in a path of the electromagnetic radiation passing through the window or facade, the window insert comprising an electrically dimmable assembly and photovoltaic device including a photosensitive layer having peak absorption between 250 nm and 450 nm and an average transmittance of at least 50 percent in the visible region of the electromagnetic spectrum;   converting ultraviolet radiation to electrical energy with the photovoltaic device; and   powering the electrically dimmable assembly with the electrical energy to alter the transmission of visible and/or infrared radiation through the window insert.   
     
     
         2 . The method of  claim 1 , wherein the photosensitive layer comprises an organic electron donor and an organic electron acceptor, and the photovoltaic device comprises a single junction architecture generating an open circuit voltage (V OC ) of at least 1.4 V. 
     
     
         3 . The method of  claim 1 , wherein the photosensitive layer has a peak emission in the range of 500 nm to 1000 nm. 
     
     
         4 . The method of  claim 3 , wherein the photosensitive layer comprises one or more contorted hexabenzocoronene (cHBC) derivatives as luminophores embedded in a polymer matrix. 
     
     
         5 . The method of  claim 4 , wherein the luminophore is tetrabenzofuranyldibenzocoronene. 
     
     
         6 . The method of  claim 4 , wherein the polymer matrix is at least 50% polymethyl methacrylate (PMMA) by mass. 
     
     
         7 . The method of  claim 4 , wherein the polymer matrix is at least 50% polyvinyl butyral by mass. 
     
     
         8 . The method of  claim 4 , wherein the photosensitive layer is a free-standing film that can be applied to or laminated by one or more glass sheets. 
     
     
         9 . The method of  claim 4 , wherein the photosensitive layer is encapsulated between two pieces of glass. 
     
     
         10 . The method of  claim 4 , wherein the photosensitive layer is coupled to edge-mounted photovoltaic devices for harvesting of visible light emitted by the luminophores and waveguided by the polymer matrix or one or more glass substrates. 
     
     
         11 . The method of  claim 1 , wherein the window insert is held by a frame that is mechanically fastened to an installed window or facade element. 
     
     
         12 . The method of  claim 1 , wherein the window insert is removable from the path of electromagnetic radiation.