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p>
Although high-temperature operation (i.e., beyond 150�C) is of great interest for many electronics applications, achieving stable carrier mobilities for organic semiconductors at elevated temperatures is fundamentally challenging. Here, we report a general strategy to make thermally stable high-temperature semiconducting polymer blends, composed of interpenetrating semicrystalline conjugated polymers and high glass-transition temperature insulating matrices. When properly engineered, such polymer blends display a temperature-insensitive charge transport behavior with hole mobility exceeding 2.0 cm<
sup>
2<
/sup>
/V�s across a wide temperature range from room temperature up to 220�C in thin-film transistors.<
/p>