Solar thermal receivers/collectors are designed to absorb as much sunlight as possible (e.g. increasing energy inputs) while minimizing heat loss and pumping energy (e.g. reducing energy losses). While nanofluid-based receivers have been proposed as an elegant solution for increasing energy inputs, only half the challenge for overall performance has been investigated in detail in the literature. Reducing energy losses is the other important, but generally overlooked factor. This thesis explores the development/fabrication of specifically engineered receivers in which these energy losses can be decreased as compared to conventional nanofluid-based direct absorption solar collectors (DASCs). First, increased pumping power was tackled by using micropatterned superhydrophobic microchannels. This study revealed up to a 17 % reduction in the pressure drop for the tested flow rates as compared to a smooth microchannel and water. Next, reflection losses of such receivers were targeted via an optically optimized single-layer anti-reflective (AR) coating. For this, one type of low-cost, single-layer MgF2 AR coating was studied from both a technical and practical perspective (e.g. including durability tests). This enabled the solar weighted reflection to be reduced to ~2.3 %. Third, a multi-functional glass cover coated with indium tin oxide (ITO) was proposed to simultaneously boast anti-reflectivity and emissive selectivity, with the potential for self-cleaning. Last, this thesis investigated the implications of each mentioned modification on the overall efficiency, using a linear efficiency equation, which takes into account the hydraulic dissipated energy. Based on this modeling, it was found that the combination of the tested nanofluid, superhydrophobic bottom surface, and a durable anti-reflective coating with similar optical property of MgF2 can enhance efficiency by up to 10 % (at a nominal flow rate) compared to water flowing on non-patterned microchannel. Overall, this thesis developed promising solutions to many of the long-standing limitations of nanofluid-based solar receivers by focusing on minimizing energy losses.