QD-OLED
Blue OLED, red and green quantum dots.
A blue OLED emitter layer sits behind a quantum-dot layer. Red and green dots convert blue light into the other primary colours. Light is converted, not filtered, so very little energy is wasted. The result is a brighter OLED with a wider colour gamut.
Made by Samsung Display. Used in Samsung S95, S90, S85 series and Sony A95-series.
WOLED
White OLED, RGBW colour filter.
A white OLED emitter sits behind a red, green, blue, and white colour filter. The filter blocks the wavelengths each pixel does not need. Less efficient than QD-OLED but very mature, with excellent uniformity and proven reliability across more than a decade of production.
Made by LG Display. Used in LG C, G, B, M series, Sony A80-series, Panasonic flagships. LG G5 introduces Primary RGB Tandem WOLED, the brightest WOLED yet.