NOVELTY - A 2-(5-(thiolan-2-yl)selenophen-2-yl)thiolane derivative (I), is new.    USE - New 2-(5-(thiolan-2-yl)selenophen-2-yl)thiolane derivative is used as organic photoelectric material for preparing active layer for solar cell, field effect transistor, organic light-emitting diode and photovoltaic device (all claimed).    ADVANTAGE - The 2-(5-(thiolan-2-yl)selenophen-2-yl)thiolane derivative is prepared by simple and easy process, and provides organic photoelectric material having excellent photoelectric conversion efficiency of 8.4%.    DETAILED DESCRIPTION - A 2-(5-(thiolan-2-yl)selenophen-2-yl)thiolane derivative of formula (I), is new.    R1,R2=H, 1-30C alkoxy, 1-30C alkylthio, halo-1-30C alkyl, halo-3-30C cycloalkyl, halo-1-30C alkoxy, halo-1-30C alkylthio, or 3-30C cycloalkyl or 1-30C alkyl (both optionally substituted by aryl, heteroaryl, heteroalicyclyl, hydroxy, alkoxy, aryloxy, mercapto, alkylthio, arylthio, cyano, halo, carbonyl, thiocarbonyl, O-carbamoyl, N-carbamoyl, O-thiocarbamoyl, N-thiocarbamoyl, C-amido, N-acylamino, S-sulfonamido, N-sulfonamido, C-carboxy, O-carboxy, isocyanato, thiocyanato, diisothiocyanato, nitro, silyl, trihalomethanesulfonyl, -NR'R", mono or di-substituted amino, amino protecting group or cycloalkyl (optionally substituted by aryl, heteroaryl, heteroalicyclyl, hydroxy, alkoxy, aryloxy, mercapto, alkylthio, arylthio, cyano, halo, carbonyl, thiocarbonyl, O-carbamoyl, N-carbamoyl, O-thiocarbamoyl, N-thiocarbamoyl, C-amido, N-acylamino, S-sulfonamido, N-sulfonamido, C-carboxy, O-carboxy, isocyanato, thiocyanato, diisothiocyanato, nitro, silyl, trihalomethanesulfonyl, -NR'R", mono or di-substituted amino or amino protecting group));    n=1-5;    A1,A2=group chosen from groups of formulae (i)-(iii);    R3=H, 1-30C alkoxy, 1-30C alkylthio, bromo-, chloro-, fluoro- or iodo-substituted derivative, or 1-30C alkyl or 3-30C cycloalkyl (both optionally substituted);and    R',R"=not defined.    N.B: R' and R" are not defined. An INDEPENDENT CLAIM is included for preparation of 2-(5-(thiolan-2-yl)selenophen-2-yl)thiolane derivative (I).