I want to know the answer to the following question:
In what decade were breakthroughs made that brought in the modern era of GaN-based optoelectronic devices?
All the background I'm provided with is that "In the late 1980s, key breakthroughs in GaN epitaxial growth and p-type doping ushered in the modern era of GaN-based optoelectronic devices.". Is that enough to answer the question?