Table 4. Optical properties of PI films.

Diamine	(I) BPADA				(II) HBPDA
	Thicknessa (μm)	λ o b (nm)	500 nmtrans (%)	YIc	Thickness (μm)	λ o (nm)	500 nmtrans (%)	YI
BZ	40	397	61	38	41	351	79	18
FDN	39	380	87	3	38	331	90	1
APS	38	389	81	20	37	339	83	10
AHP	41	383	83	10	39	334	86	2

^aFilm thickness.

^bCut-off wavelength.

^cYellow index.