NOVELTY - Photocurable composition comprises a photocurable monomer, and/or a silicon-containing monomer or oligomer, where the silicon-containing monomer is (I).    USE - The photocurable composition is useful for: a member of an apparatus, where the member includes one or more of a flexible organic LED, an organic LED, an illumination device, a metal sensor pad, a microdisc laser, an electrochromic apparatus, a photochromic device, a microelectromechanical system, a solar cell, an integrated circuit, a charge coupled device, a light emitting polymer, or a LED (all claimed); and forming organic barrier layer for sealing or encapsulating the apparatus such as a flexible display apparatus.    ADVANTAGE - The photocurable composition exhibits high energy and humidity, good light transmittance, moisture and oxygen barrier and smoothing properties, and improved durability.    DETAILED DESCRIPTION - Photocurable composition comprises a photocurable monomer, and/or a silicon-containing monomer or oligomer, where the silicon-containing monomer is of formula (Z1-R1-(Si(Y1)(Y2))-X1-((Si(Y3)(Y4))-X2-)n-(Si(Y5)(Y6))-R2-Z2) (I).    X1-X3 = O, S, N-H or N-R1a;    R1a = 1-20C-alkyl (optionally substituted);    R1, R2 = 1-20C-alkylene, 1-30C-alkyl ether, 1-30C-alkylamine, 1-30C-alkyl sulfide, 6-30C-arylene, 7-30C-arylalkylene or 1-20C-alkoxylene (all optionally substituted) or single bond;    Y1-Y6 = 1-30C-alkyl, 1-30C-alkyl ether, 1-30C-dialkylamine, 1-30C-alkyl sulfide, 6-30C-aryl, 7-30C-aryl alkyl, 1-30C-alkylene or 1-30C-alkoxylene (all optionally substituted), or a silicon compound of formula (-(Si(R4)(R3)(R5))) (II) or (-X3-(Si(R7)(R6)(R8))) (III);    R3-R8 = 1-30C-alkyl, 1-30C-alkyl ether, 1-30C-dialkylamine, 1-30C-alkyl sulfide, 6-30C-aryl or 7-30C-aryl alkyl (all optionally substituted) or H;    Z1, Z2 = (-O-C(=O)-C(CH2)-R9) (IV);    R9 = 1-30C-alkyl (optionally substituted); and    n = 0-30.    An INDEPENDENT CLAIM is included for an apparatus comprising an encapsulated member (20) including a barrier stack (30) on the member, where the barrier stack includes an inorganic barrier layer (31) and an organic barrier layer (32), and the organic barrier layer has an outgas generation amount of less than 2000 ppm.    DESCRIPTION OF DRAWING(S) - The figure shows a sectional view of an encapsulated apparatus.    Substrate (10)    Encapsulated member (20)    Barrier stack (30)    Inorganic barrier layer (31)    Organic barrier layer. (32)