GaN based emissive microdisplays: A very promising technology for compact, ultra high brightness display systems
High brightness GaN based emissive microdisplays can be fabricated with different approaches that are listed and described. They consist either of hybridizing a GaN LED array on a CMOS circuit or building a monolithic component on a single substrate. Using the hybridization approach, two types of 10 mm pixel pitch GaN microdisplay prototypes were developed: (1) directly driven, 300 x 252 pixels and (2) active matrix, 873 x 500 pixels. Brightness as high as 1 x 106 and 1 x 107 cd/m2 for blue and green arrays, respectively, were reached. GaN based emissive microdisplays are suitable for augmented reality systems or head up displays, but some challenges remain before they can be put in production.