I'm curious why there is no solid state detector? We've had tons of advancements in solid state optical devices like emitters. But have there been no advancements to radiation detection in 100 years since the G-M tube was invented?
There absolutely are solid state detectors and major innovations! People nowadays use scintillator detectors with photomultipliers, for things like research and more precise counters.
Scintillation counters use some material, often a plastic, that "scintillate," meaning it can absorb high energy particles and re-emit them as lower energy photons. The low energy photons are then amplified though various means, from photoelectric tubes similar to earlier night vision technology, to all integrated silicon chips [0]
In general, scintillation counters have the benefit of more precision and better ability to detect alpha particles (like GM tubes with quartz windows) and also don't require high voltages to drive. I think they're a cool example of technology modernization, where we go from the somewhat janky, almost steampunk aesthetic of soviet geiger tubes driven by crude looking flyback transformers, to low voltage, highly precise, extremely integrated and miniaturized modern detectors powered by semiconductors.
