Export data to excel on Zend Framework

IndexController.php

<?php

class IndexController extends Zend_Controller_Action
{
    public function exportXlsAction()
    {
        set_time_limit( 0 );

        $model = new Default_Model_SomeModel();
        $data = $model->getData();

        $filename = APPLICATION_PATH . "/tmp/excel-" . date( "m-d-Y" ) . ".xls";

        $realPath = realpath( $filename );

        if ( false === $realPath )
        {
            touch( $filename );
            chmod( $filename, 0777 );
        }

        $filename = realpath( $filename );
        $handle = fopen( $filename, "w" );
        $finalData = array();
        
        foreach ( $data AS $row )
        {
            $finalData[] = array(
                utf8_decode( $row["col1"] ), // For chars with accents.
                utf8_decode( $row["col2"] ),
                utf8_decode( $row["col3"] ),
            );
        }

        foreach ( $finalData AS $finalRow )
        {
            fputcsv( $handle, $finalRow, "\t" );
        }

        fclose( $handle );

        $this->_helper->layout->disableLayout();
        $this->_helper->viewRenderer->setNoRender();

        $this->getResponse()->setRawHeader( "Content-Type: application/vnd.ms-excel; charset=UTF-8" )
            ->setRawHeader( "Content-Disposition: attachment; filename=excel.xls" )
            ->setRawHeader( "Content-Transfer-Encoding: binary" )
            ->setRawHeader( "Expires: 0" )
            ->setRawHeader( "Cache-Control: must-revalidate, post-check=0, pre-check=0" )
            ->setRawHeader( "Pragma: public" )
            ->setRawHeader( "Content-Length: " . filesize( $filename ) )
            ->sendResponse();

        readfile( $filename ); exit();
    }
}

Its is giving me "Action Helper by name Layout not found" error? any solution?
I am new to Zend Framwork 1.2.

It generates excel file but when open directely it generates non english content like damage file.what i should do?