Diffraction grating, organic EL element using the same, and manufacturing methods thereof

A method for manufacturing a diffraction grating, comprising:

• a step of applying a curable resin onto a transparent supporting substrate, then curing the curable resin with a master block being pressed thereto, and thereafter detaching the master block, thereby stacking, on the transparent supporting substrate, a cured resin layer having concavities and convexities formed thereon, wherein
• the master block is obtained by any of the following methods (A) and (B) for manufacturing a master block:
• (A) the method (A) for manufacturing a master block comprising the steps of:
• applying a block copolymer solution comprising a block copolymer and a solvent onto a base member, the block copolymer having a first polymer segment made of a first homopolymer and a second polymer segment made of a second homopolymer having a solubility parameter which is higher than a solubility parameter of the first homopolymer by 0.1 to 10 (cal/cm3)1/2, and satisfying all the following conditions (i) to (iii):
• (i) a number average molecular weight is 500000 or more,
• (ii) a molecular weight distribution (Mw/Mn) is 1.5 or less, and
• (iii) a volume ratio between the first polymer segment and the second polymer segment (the first polymer segment:the second polymer segment) is 3:7 to 7:3;
• and
• forming a micro phase separation structure of the block copolymer by drying a coating film on the base member, thereby obtaining a first master block having concavities and convexities formed on a surface thereof;
• and
• (B) the method (B) for manufacturing a master block comprising the steps of:
• a method comprising the steps of:
• forming a vapor-deposition film under a temperature condition of 70° C. or above on a surface of a polymer film made of a polymer whose volume changes by heat, and then cooling the polymer film and the vapor-deposition film, thereby forming concavities and convexities of wrinkles on a surface of the vapor-deposition film;
• and
• attaching a master block material onto the vapor-deposition film, then curing the master block material, and thereafter detaching the cured master block material from the vapor-deposition film, thereby obtaining a master block.