An optoelectronic device (LV) with a reflective composite material (V) having a carrier (1) consisting of aluminium, having an interlayer (2) composed of aluminium oxide present on one side (A) of the carrier (1) and having a reflection-boosting optically active multilayer system (3) that has been applied via the interlayer (2). The interlayer (2) consisting of aluminium oxide has a thickness (D2) in the range from 5 nm to 200 nm and that, on the opposite side (B) of the carrier (1) from the reflection-boosting optically active multilayer system (3), a superficial layer (9) of a metal or metal alloy having, at 25° C., a specific electrical resistivity of not more than 1.2*10−1 Ωmm2/m has been applied. The thickness (D9) of the superficially applied layer (9) is in the range from 10 nm to 5.0 μm. For an optoelectronic device (LV), the leadframe (LF) has a metallic material with an aluminium carrier (1), on the surface (A) of which a metallic joining layer (FA) not consisting of aluminium has been applied locally at the bonding site (SP) of an electronic surface-mounted device (SMD) to a wire (D).