High mobility p-type transparent conducting materials (TCMs) have eluded researchers for decades. The unlikely bedfellows of optical transparency, valence band dispersion and correct point defect chemistry prove difficult to unite, with this strict requirement precluding the vast majority of materials from ever displaying p-type transparent conducting properties. Early efforts focused on the development of p-type oxides, such as CuAlO 2 , attempting to mimic the wide optical band gap of the n-type transparent conducting oxides. However, CuAlO 2 and other delafossite materials are plagued by low mobility and conductivity due to the polaronic nature of the holes generated in these systems, which are bound to Cu states at the valence band maximum. Several other oxides have been considered as p-type transparent conductors with varying degrees of success: Li-doped NiO can reach hole concentrations on the order of 1 × 10 21 cm -3 and conductivity up to 11 S cm -1 , but mobility is less than 0.05 cm 2 V -1 s -1 and transmission drops to 50% upon doping; SnO is a reasonably good p-type TCM, with mobility around 7 cm 2 V -1 s -1 at 1×10 17 cm -3 carriers, and can also be doped n-type, but incurs stability issues due to the presence of Sn(II) (a problem which pervades ternary Sn(II) materials also); quasi-closed shell 𝑑 and 𝑑 materials such as Sr-doped LaCrO 3 and the ZnM 2 O 4 spinels (M = Co, Rh, Ir); and Ba 2 BiTaO 6 , which shows excellent mobility (up to 30 cm 2 V -1 s -1 ) due to strong Bi 6𝑠 2 -O 2𝑝 interaction at the valence band, but the carrier density is limited to 1 × 10 14 cm -3 . Therefore, research into non-oxides has taken centre stage in recent years, in the hope that greater valence band delocalisation and bond covalency can improve hole mobility while simultaneously generating enough carriers to enable degenerate conductivity.