The high electricity consumption and limited size of multifunctional wearable electronics for health monitoring, telecommunication, and personal drug-delivering have induced new challenges for the device's operating life span. The conventional rigid and bulky photovoltaics (PVs) have restricted their integration with wearable devices and have hindered their niche applications in portable, lightweight, and flexible electronics. Organic photovoltaics (OPVs), with their flexibility, excellent mechanical robustness, high power-per-weight ratios, and economical fabrication processes, have aroused attention in the field. OPVs are born to bring energy supplies to a versatile selection of substrates as portable power sources. In the past two decades, the efficiency of OPVs has come from below 5% to approaching 20%. However, in the race of power conversion efficiency (PCE), the emphasis is mainly on the design of active layers and the related device architecture. The uniqueness of OPVs: the side-group tunability of the donor-acceptor materials allows OPVs a selective absorption for solar conversion either in UV or NIR range. This provides OPVs a wearable way of solar harvesting and a visible light transparent/ semitransparent fashion. This opens a window for playing around with the incoming and penetrating photons. In this work, the focus is on light environment management enhanced PCE for wearable PVs via the luminescent solar concentrator (LSC) add-ons, using amphiphilic polymer conetworks (APCNs).

In our previous work [1,2,3], APCNs are employed as polymer matrices for wearable LSCs owing to their flexibility and wearability. Furthermore, with the assistance of APCNs’ nanophase-separated hydrophobic and hydrophilic domains, hydrophobic (Lumogen Red, acceptor) and hydrophilic (fluorescein, donor) luminescent materials are loaded in adjacent nanometer-separated domains. This results in high ET rates and broadens the acceptor’s absorption range, rendering a more efficient down-conversion emission. We could achieve high ET rates between dye pairs via FRET and photon recycling with a straightforward synthesis procedure. These two energy transfer mechanisms were confirmed by steady-state and dynamic photoluminescence methods, showing a ~100% total ET between donors and acceptors. The developed nanostructure-assisted ET system is not limited to the dyes investigated here but can be directly extended to a wide variety of dyes (Rhodamine B, HPTS, DCM, and Lumogen Yellow) and quantum dots (CsPbBr3 and CdSe/ZnS).

In this work, we take a step further by introducing APCNs into optoelectronic devices. The OPVs donor-acceptor polymers/small molecules and luminescent dyes are loaded into the hydrophobic and hydrophilic domains of APCNs, respectively. Depending on the spectral responsiveness of the selected OPVs active materials, the LSCs dye is then picked for optimal emission wavelength with the absorption of OPVs. With this geometry, each system (OPVs and LSCs) is located in the isolated/ individual domain of APCNs, rendering a brand-new architecture of combining OPVs with the relevant LSCs to boost device efficiency in a single polymeric matrix while preventing the intersystem interpretation and quenching. This delivers an efficient and novel architecture wearable solar energy harvester that utilizes APCNs biphasic nature and wearability.